Lambda probe models are special samples oxygen sensor, which is necessary for the correct operation of the electronic system in the fuel combustion chambers. Thanks to this element, the system manages to balance and constantly monitor the percentage ratio between oxygen and gasoline. With the help of a probe, the electronic system constantly corrects the structure supplied to the engine fuel mixture, and also warns of destabilization in the engine working process.

When operating this fragile device in very aggressive environments, it gradually wears out and requires replacement after two years of use. By replacing the lambda probe, you can avoid engine damage. With a periodic check of the lambda probe, you will have a real guarantor of the stable operation of your car.

How does a lambda probe work?

The main purpose of the sensor is to timely determine the chemical composition of the exhaust gas and determine the level of the percentage of oxygen in it. In order to avoid problems in the operation of the engine, this indicator must be kept in the range of 0.1-0.3%.

Types of lambda probes

Now on the automotive equipment market, you can increasingly find only 2 variations of the device:

1. The probe is based on a two-channel layout type. This type of sensor was mainly used in machines from the 80s, and is also used on modern cars economy class.
2. Lambda sensor of wideband type. This type of probe is used as standard in 70% of middle and upper class machines. This type of sensor not only accurately detects any deviations from the norm between the elements, but also informs the system in a timely manner for instant position stabilization.

All samples of modern lambda probes are mounted in a special exhaust manifold, where the hoses and pipes are directly connected. This positioning of the sensor allows for maximum performance and accuracy of this instrument.

The main task of any lambda probe is to significantly increase the working resources of the car by reducing fuel consumption and increasing the stability of maintaining speed during idle. As a result, this sensor does not give specific values \u200b\u200bof the parameters of the fuel mixture, but reacts only when the obtained values \u200b\u200bare destabilized. After detecting a discrepancy with the set parameters, the sensor transmits information to the central unit, which corrects the fuel-air ratio.

Advice: if it was made by you or by another car, be sure to check the correct operation of the probe. If this part is replaced, the correct operation of the device may be impaired.

The main symptoms of a lambda probe malfunction

Among the signs that make it possible to determine in advance whether the probe is working properly or not, the following are distinguished:

• The appearance of instability when the engine is running (the engine starts to pick up speed sharply and also stalls sharply);
• Deterioration of the quality of the fuel mixture pumped into the cylinder system (this leads to excessive consumption of fuel);
• Uncontrolled and ineffective fuel supply (the appearance of malfunctions in the operation of the engine and the electronic system of the machine);
• The gradual appearance of intermittent engine operation on idling;
• Decrease in the efficiency of the engine at maximum speed;
• Problems in the operation of electronic systems (malfunctions in the sensor lead to unstable operation of the engine compartments, since the signal about the malfunction is transmitted with a delay);
• The presence of periodic "twitching" of the car;
• The appearance of incomprehensible pops when the engine is running;
• Untimely (delayed) response of the vehicle's engine systems to pressing the accelerator pedal;
• The appearance of a constantly flashing light on the sensor malfunction on the central instrument panel.

In case you find that your vehicle one or more of these reasons, you should consider replacing this device.

Advice: One of the main indicators that the lambda probe is completely out of order is a constant sharp drop in engine power when accelerating.

Repair or replace the lambda probe?

As well as the repair of the lambda sensor should be carried out in a car service. However, in most cases, this spare part is completely replaced, since it simply cannot be repaired further. The problem is high price original sensors from an authorized dealer.

As a result, most motorists decide to switch to using a universal sensor that fits almost any brand of car and is much cheaper than its native counterparts. In addition, if you want to save money, you can purchase a lambda probe from a showdown. Used sensors are shown there, however they may have an extended warranty period. Also, you can immediately purchase a full-fledged model of the exhaust manifold, in which the lambda probe is already installed.

If the problem lies only in the presence of a small error in the operation of the sensor, you can quickly repair it yourself. The main signs of a malfunction are associated with its strong pollution during the settling of fuel combustion products. In order to understand whether the probe has affected the operation or not, it is enough just to show it to the specialists at the auto center. After the experts confirm the fact that the lambda probe you removed is working, you just have to carefully clean it from dust and burnt deposits, and then put it back.

DIY lambda sensor repair steps

To dismantle the lambda probe, it will be necessary to first heat its surface to the limit of 60 degrees. Then carefully remove it and additionally take out the protective cap. After that, you can start cleaning with phosphoric acid, which helps to easily cope with any (even the most persistent) combustible deposits.

Advice: at the end of work, before installation, do not forget to pre-lubricate the threads with a special sealant to ensure complete tightness of the product.

Video: how to check a lambda probe?

Oxygen sensor is a device in the engine exhaust manifold internal combustion, which allows you to estimate how much free oxygen is left in the exhaust mixture.

This sensor also has another name. Lambda probe what is this design and where did this name come from. The sensor is based on a solid ceramic electrolyte made of zirconium dioxide, which in turn is coated with yttrium oxide. Above all, porous, conductive platinum electrodes were deposited on the ceramic element.

Its principle of operation is like that of a galvanic cell. After being installed in the exhaust manifold, it heats up in the flow exhaust gases up to 300 - 400 degrees. It is in the heated state that the zirconium electrolyte receives conductivity and ensures its normal functioning. A lambda probe is installed in such a way that one of the electrodes breathes outside air, the other with a mixture of exhaust gases. When the amount of oxygen changes on one of the electrodes, a potential difference arises, which is transmitted as a signal to the engine control system, which regulates the fuel supply for injection.

In the science of the ratio of elements in nature, stoichiometry, lambda means the ratio of the actual amount of air to the required one.

Theoretically optimal ratio - this is when the lambda is equal to 1, that is, there is as much real air in the mixture as needed.

If lambda is greater than one - it is a lean mixture if this value is less than one - rich mixture, that is, there is an excess of gasoline in the mixture, there is not enough oxygen for its combustion.

For power unit the car is considered optimal lambda equal to 14.7: 1, that is, a lean mixture. This is due to the fact that a certain amount of oxygen is required for efficient combustion of CO and CH on the catalyst. A modern lambda probe VAZ 2114 works as a threshold element.

Oxygen sensor VAZ 2114, design and application features

Since the oxygen sensor is turned on after heating the working element to 350 degrees, the first samples were tried to be placed as close to the exhaust manifold as possible. Over time, the sensor was modernized and a heating element was built into it, which brought it into operation much faster and now, the question is where is the lambda probe located in exhaust systemis not that important. Structurally, a modern oxygen sensor consists of the following elements.

1. Ceramic tips with protective screens and holes for sampling, on the one hand, exhaust gases, on the other - atmospheric air, enclosed in a ceramic insulator in the middle part. They are the main working element of the entire device. These are exactly the electrodes from which the potential difference is removed.
2. A conductive heating element is located inside these tips.
3. In the middle there is an electrical signal collector.
4. All elements, with the exception of the sensitive parts of the ceramic tips, are enclosed in a threaded metal case, which is designed to fix the sensor in the receiver tube.
5. Currently, modern sensors are equipped with a set of wires secured with a sealing collar. Such sensors are called a four-wire lambda probe. Two white wires are contacts of the heating system, one black - signal and black (or white) with a strip - "ground". In earlier samples that are still used, the potential difference was determined between the wire that went from the sensor to the ECU and the ground on the sensor body. For this, the sensor was smeared with a specific conductive grease before screwing in at the attachment point. However, the high temperature burned out the grease and the sensor's sensitivity suffered. Now this drawback has been eliminated.

The set of wires for the oxygen sensor at its other end, through the plug box, is connected to the electronic on-board device, which asks the lambda probe for data on the state of the mixture with a frequency of 2 times per second at idle speed and more often with increasing revs. Analyzing the obtained data on the presence of oxygen in the exhaust gas mixture, the ECU adjusts the amount of fuel injected into the engine, making the mixture richer or leaner, depending on the incoming oxygen sensor signals. He strives for the optimal value of 14.7: 1, which is laid down in his program.

The performance of the sensor is verified by testing with a meter. The lower signal level should be 0.1 - 0.2 V, the upper one - within 0.8 - 0.9 V. The guaranteed performance of these sensors is very high. Symptoms of a malfunction of a lambda probe manufactured in accordance with GOST begin to appear not earlier than after a run of 80 thousand kilometers, and on average they can withstand a load of 160 thousand kilometers. However, according to service book VAZ 2114 is recommended after a run of 80 thousand km. The fact is that although it continues to maintain its performance, its sensitivity is still significantly reduced, which means that fuel consumption indicators deteriorate, for example.

How does the lambda probe affect the operation of the engine, signs of its malfunction

The oxygen sensor lambda probe has a direct effect on the stable operation of the engine, maintaining the correct mixture for the engine:

• the engine runs steadily, without hesitation, idling;
• at hard pressing the gas pedal, there is a timely restructuring in the engine power supply with a mixture corresponding to the changing speed, so there are no jerks and triplets;
• the best burned exhaust gases are emitted into the atmosphere due to the efficient operation of the catalyst, which burns harmful substances in the exhaust pipe.

To ensure normal conditions for the operation of the sensor and extend its resource, a number of conditions must be observed:

1. Use only the gasoline recommended for the VAZ 2114.
2. When working with additives, check their quality and permission for use.
3. Never use sealants, especially silicone, for fixing the sensor.
4. Avoid multiple startup attempts in a short period of time.
5. Do not disconnect spark plugs when checking cylinder operation.
6. Prevent overheating of the exhaust system due to the accumulation of unburned fuel in it, the sensor can withstand temperatures only up to 950 degrees.
7. Do not wash handpieces with any of the chemically active liquids.
8. Ensure that the tightness is maintained at the junction of the sensor with the pipe.

Signs by which you can determine that you need to replace the VAZ 2114 oxygen sensor can be:

• on low gas, the engine runs unstable, the speed floats or the engine stalls;
• there is a steady increase in fuel consumption under standard conditions;
• there was a deterioration in the dynamic characteristics of the car;
• characteristic crackles in the catalyst area after the engine is turned off, as well as the specific smell of rotten eggs due to a large amount of unburned gasoline entering the catalyst;
• a signal on the on-board computer about errors related to the failure of the lambda probe.

Most often, with a faulty oxygen sensor, all of the above signs should appear, and when a situation arises with its replacement, the question will arise which oxygen sensor is on the VAZ 2114. Depending on the year of manufacture of the car, the exhaust system can contain both single-wire sensors with a mass from the body, so and four-wire. The price of a VAZ 2114 lambda probe in this case can range from 1200 to 3000 thousand rubles.

When replacing the sensor, check it by testing it on an appropriate device, the contacts in the heating line may be damaged and then the oxygen sensor can be repaired.

If a strong carbon deposit is found on the sensor after removal and it shows that the potential difference is not very different from the permissible ones, then this carbon deposit can be removed. To do this, heat the sensor very much, and then cool it down sharply. The carbon should crack and fly around, wrap it with a soft bone.

Some motorists are interested in car mechanics how to turn off the VAZ 2114 lambda probe. The procedure itself is simple, but the need for this is in great doubt. In this case, the ECU begins to supply gasoline for injection in averaged values \u200b\u200band this will immediately affect the stable operation of the engine, increase fuel consumption and deteriorate exhaust characteristics. Not to mention the need for a flashing on-board computer, since it will constantly give an error associated with the absence of an oxygen sensor.

The efficiency of a car engine depends on the quality of combustion of the gas-air mixture. The exact proportions, and accordingly the rational effect of work, are regulated by an oxygen sensor - a lambda probe. Understanding the design and principle of operation of the device is necessary for self-determination and correction of defects. The safety of operating your own car depends on how quickly the causes / consequences of a malfunction of the lambda probe are identified and eliminated.

Only vehicles with injection engines... Location in the exhaust pipe after the catalyst. A dual configuration oxygen sensor can be located upstream of the catalyst, providing enhanced control over the gas composition, thereby enabling more efficient instrument operation.

Operating principle:

• The electronics of the car, which is responsible for dosing fuel, sends a signal about the demand for supply to the nozzle.
• Accordingly, the oxygen device determines the right amount of air to form the correct mixture.
• The settings of the device allow you to comply with the requirements for the environmental and economic component of the issue of car operation - to exclude excessive fuel consumption and gas pollution of the environment.

Modern cars are equipped with advanced devices - catalysts and paired sensors - that help reduce the negative effects of exhaust emissions and the consumption of expensive fuels and lubricants. However, in the event of a breakdown expensive option sensor, "treatment" will cost a considerable amount.

Lambda probe design

Externally, the device looks like a steel elongated body-electrode with output wires and platinum-plated. Internally, the device is as follows:

• A contact that connects wires to an electrical element.
• Dielectric seal for safety with air inlet.
• A hidden zirconium electrode enclosed in a ceramic tip, heated under the action of a current of up to 300-1000 degrees.
• Protective temperature shield with exhaust gas outlet.

Sensors can be point-to-point or broadband. The device classification does not affect the external and internal organizationhowever, makes a significant difference in how it works. The device described above is a two-point one, the second is an upgraded version.

More about him:

In addition to the two-point design, the sensor also contains an injection element. The meaning of the work is that when the constant voltage fluctuates between the electrodes, a signal is sent to the control unit. The supply of current to the injection element is increased or decreased, a portion of air enters the analysis gap, where the level of concentration of exhaust vapors is determined.

Lambda probe malfunction symptoms

Eternal, created by human hands - does not exist. Any technique designed for subtle analysis can fail for many reasons. Oxygen sensors are no exception.

Let's consider in detail:

• Increased CO level. Determine the concentration yourself, perhaps only with the help of instruments. Almost always, the indicators indicate a probe malfunction.
• Increased fuel consumption. Injection vehicles are equipped with a board indicating the amount of fuel consumed. Also, the increase can be judged if the refueling frequency exceeds the usual one.
• The light signaling, oriented to the operation of the lambda probe, is constantly on. This is a light bulb Check Engine.

In addition to the described signs of destabilization of the oxygen sensor operation, the quality of the exhaust gas can be assessed visually - light smoke indicates oversaturation of air in the mixture, clouds of thick black smoke - on the contrary, excessive fuel consumption.

Reasons for the breakdown of the oxygen sensor

Since the device directly works with fuel combustion products, the quality of it (fuel) cannot but affect the productivity and result. A combustible product that does not meet all the established GOSTs and regulations often serves as the primary reason why the sensor does not show reliable results or, in general, fails. Lead is deposited on the surface of the electrodes, making the lambda probe insensitive to detection.

Other reasons:

• Mechanical failure... From vibration and / or active use of the car, the sensor body is damaged. The device cannot be repaired or replaced. It will be much more rational to purchase and install a new one.
• Incorrect work fuel system ... Over time, the soot formed as a result of incomplete combustion of fuel settles on the housing and gets inside the inlet holes of the probe. The readings become incorrect. The problem is initially stopped by timely cleaning, however, if it occurs constantly, then it will not be possible to get rid of it - oxygen sensor, it is a consumable part that must be replaced in time.

To achieve the serviceability of the car at all its nodes, it is important to send your own "horse" for periodic diagnostics to identify problems. Then, the functionality of the devices, including the lambda probe, will be preserved.

How to independently check a lambda probe for serviceability

Only qualified diagnostics can give a reliable result about the cause of the breakdown. However, it is possible to understand that the sensor is faulty on your own. For this:

Learn the manual. The attached instructions for the device contain the parameters of the oxygen sensor. It is important to focus on them.

• Opening and inspecting engine compartmentfind the probe. External contamination in the form of soot and / or light deposits will indicate lead deposition and abnormal fuel system performance. In this case, the device is completely changed and other parts of the car are diagnosed, since the ingress of dirt and heavy metal on them does not bode well.
• If the tip is clean, continue the test. For this, the sensor is disconnected and connected to a voltmeter. The car is started, increasing the speed to 2500 / min and reduced to 200. The readings of the working sensor vary in the range of 0.8–0.9 W. Lack of response or lower values \u200b\u200bindicate a malfunction.

You can also check the probe using a lean mixture, provoking a suction in the vacuum tube. In this case, the voltmeter readings with a working device are low - up to 0.2 W and below.

The dynamic indicators of the 0.5 W sensor connected to the fuel supply system in parallel with the voltmeter indicate the operability of the device. Other values \u200b\u200bwill indicate a malfunction.

DIY oxygen sensor trick

By avoiding delaying regular maintenance - in particular, for a lambda sensor, it occurs every 30 thousand km - the car owner ensures uninterrupted operation of the device. After 100 thousand km, he needs a complete replacement.

If everything is in order with a conscientious attitude to the car, then it will not be possible to control the quality of the fuel. As a result, carbon deposits or lead deposits will cause the Check Engine light to keep responding. So that the car owner does not bother, the problem is solved with the help of trickery.

Types of structures

Depending on financial capabilities, they make bronze parts of the spacers with their own hands, buy technological electronic options, arrange a flashing of the entire control unit. Let's describe each method in detail:

Homemade device

The body is a bronze piece with high temperature resistance. The dimensions are strictly matched to the sensor in order to avoid exhaust vapor infiltration. The hole for their exit into the spacer is no more than 3 mm.

The principle of operation of the device is as follows: ceramic chips inside the cylinder covered with a catalyst layer under the influence of exhaust gas and oxygen is oxidized, which causes the concentration to decrease, and the sensor takes the value as normal. The option is budgetary, however, for cars of high price category unacceptable - in the end, automation should work for the result.

Electronic snag

Specialists in soldering circuits can "bungle" a snag for an oxygen sensor with their own hands. This requires a capacitor or resistor. The motorist, whose knowledge is limited, cannot use the method - a lack of understanding of the processes threatens to negatively affect the entire control unit. To resolve the issue, a ready-made structure is purchased. The principle of operation of the emulator with a microprocessor is as follows:

• The microcircuit evaluates the gas concentration and analyzes the signal from the first sensor.
• After that, it generates an impulse corresponding to the signal from the second.
• As a result, average readings are obtained without affecting normal work the control unit, since the input value is always less than the critical one.

Flashing

Deceive oxygen lambda sensor, possibly by means of a cardinal flashing of the control unit. The bottom line is that there is no reaction to the signal after the catalyst - the sensor reacts only to the state of the unit installed in front of the catalyst, that is, where exhaust vapors are absent or present in a small amount that does not affect the analysis result.

Attention! Warranty services will refuse to do the work, since this contradicts the normal maintenance of the car - any unit must work and respond to emergency situations.

This is especially true for new cars. Therefore, the firmware is purchased independently - by no means via the Internet - or installed by home-grown craftsmen. Otherwise, the damage caused to the car in the future should not cause confusion among the owner of the car.

Video review of deception

Determine the malfunction of the lambda probe video

Unfortunately, not all car owners know what a lambda probe is and what it is needed for. A lambda probe is an oxygen sensor that allows electronic system control and balance the correct ratio of air and gasoline in the combustion chambers. It is able to timely correct the structure of the fuel mixture and prevent destabilization of the engine's working process.

This rather fragile device is located in a very aggressive environment, therefore its operation must be constantly monitored, since if it breaks down, further use of the car is impossible. Periodic checking of the lambda probe will guarantee the stable operation of the vehicle.

The principle of operation of the lambda probe

The main task of the lambda probe is to determine the chemical composition of exhaust gases and the level of oxygen molecules in them. This figure should range from 0.1 to 0.3 percent. Uncontrolled exceeding of this standard value can lead to unpleasant consequences.

With the standard assembly of the car, the lambda probe is mounted in the exhaust manifold in the area of \u200b\u200bthe connection of the pipes, however, sometimes there are other variations of its installation. In principle, a different arrangement does not affect the performance of this instrument.

Today, you can find several variations of the lambda probe: with a two-channel arrangement and a broadband type. The first type is most often found on old cars produced in the 80s, as well as on new economy class models. The wideband type sensor is inherent in modern cars of the middle and upper class. Such a sensor is able not only to accurately determine the deviation from the norm of a certain element, but also to timely balance the correct ratio.

Thanks to the diligent work of such sensors, the service life of the vehicle is significantly increased, fuel consumption is reduced and the stability of maintaining idle speed is increased.

From the electrotechnical point of view, it is worth noting that the oxygen sensor is not able to create a homogeneous signal, since this is prevented by its location in the collector zone, because in the process of reaching the exhaust gases of the device a certain number of operating cycles can pass. Thus, we can say that the lambda probe rather reacts to the destabilization of the engine, which it actually subsequently notifies the central unit and takes appropriate measures.

The main symptoms of a lambda probe malfunction

The main symptom of a malfunction of the lambda probe is a change in engine operation, since after its breakdown, the quality of the supplied fuel mixture into the combustion chamber deteriorates significantly. The fuel mixture, in fact, remains uncontrolled, which is unacceptable.

The reason for the exit from the operating state of the lambda probe may be the following:

• depressurization of the case;
• penetration of outside air and exhaust gases;
• overheating of the sensor due to poor-quality painting of the engine or improper operation of the ignition system;
• obsolescence;
• incorrect or intermittent power supply that leads to the main control unit;
• mechanical damage due to improper operation of the car.

In all of the above cases, except for the last, failure occurs gradually. Therefore, those car owners who do not know how to check the lambda probe and where it is generally located, most likely, will not immediately notice the malfunction. However, for experienced drivers determining the reason for the change in engine operation is not difficult.

The gradual failure of the lambda probe can be divided into several stages. At the initial stage, the sensor ceases to function normally, that is, at certain operating moments of the motor, the device stops generating a signal, after which the idle speed is destabilized.

In other words, they begin to fluctuate in a rather wider range, which ultimately leads to a loss in the quality of the fuel mixture. At the same time, the car begins to twitch for no reason, you can also hear uncharacteristic claps of the engine, and the warning light on the instrument panel must light up. All these anomalous phenomena signal the car owner about the incorrect operation of the lambda probe.

At the second stage, the sensor stops working at all on an unheated engine, while the car will signal the driver about the problem in all possible ways. In particular, there will be a noticeable drop in power, slower response when the accelerator pedal is pressed and all the same pops from under the hood, as well as unjustified jerking of the car. However, the most significant and extremely dangerous signal of a lambda probe breakdown is engine overheating.

If all the previous signals are completely ignored, indicating a deterioration in the state of the lambda probe, its breakdown is inevitable, which will cause a large number of problems. First of all, the possibility of natural movement will suffer, fuel consumption will also significantly increase and an unpleasant pungent odor with a pronounced shade of toxicity from the exhaust pipe will appear. In modern automated vehicles, in the event of a breakdown of the oxygen sensor, emergency blocking can simply be activated, as a result of which the subsequent movement of the car becomes impossible. In such cases, only an emergency call for a tow truck can help.

However, the worst case scenario is depressurization of the sensor, since in this case the car's movement becomes impossible due to the high probability of engine breakdown and subsequent expensive repairs. During depressurization, exhaust gases instead of escaping through exhaust pipefall into the atmospheric reference air intake channel. During engine braking, the lambda probe begins to record an excess of oxygen molecules and urgently supplies a large number of negative signals, which completely disables the injection control system.

The main sign of sensor depressurization is loss of power, this is especially felt during high-speed movement, the characteristic tapping from under the hood while driving, which is accompanied by unpleasant jerks and an unpleasant smell that is emitted from the exhaust. Also, the depressurization is evidenced by the visible sediment of soot formations on the body. exhaust valves and in the area of \u200b\u200bcandles.

How to determine a malfunction of a lambda probe is described in the video:

Electronic check of a lambda probe

You can find out about the state of the lambda probe by checking it on professional equipment. For this, an electronic oscilloscope is used. Some experts determine the performance of the oxygen sensor using a multimeter, however, it can only state or deny the fact of its breakdown.

The device is checked during the full operation of the engine, since at rest the sensor will not be able to fully convey the picture of its performance. In case of even a slight deviation from the norm, it is recommended to replace the lambda probe.

Replacing the lambda probe

In most cases, a part such as a lambda probe cannot be repaired, as evidenced by statements about the impossibility of repairing from many car manufacturers... However, the overestimated cost of such a node is official dealers discourages any desire to acquire it. The optimal way out of this situation can be a universal sensor, which is much cheaper than its native analog and is suitable for almost everyone car brands... Also, as an alternative, you can purchase a sensor that was in use, but with the duration of the warranty period, or a completely exhaust manifold with a lambda probe installed in it.

However, there are cases when the lambda probe functions with a certain error due to severe pollution as a result of the settling of combustion products on it. In order to make sure that this is indeed the case, the sensor must be checked by specialists. After the lambda probe has been checked and the fact of its full operability has been confirmed, it must be removed, cleaned and installed back.

In order to dismantle the oxygen level sensor, it is necessary to warm up its surface to 50 degrees. After removal, the protective cap is removed from it and only after that you can start cleaning. It is recommended to use as a highly effective cleaning agent orthophosphoric acidthat handles even the most stubborn flammable deposits with ease. At the end of the soaking procedure, the lambda probe is rinsed in clean water, thoroughly dried and installed in place. In this case, do not forget about lubricating the threads with a special sealant, which ensures complete tightness.

It is very difficult, so it needs constant support of its efficiency and timely preventive maintenance. Therefore, in case of suspicion of a malfunction of the lambda probe, it is necessary to immediately diagnose its operability and, if the fact of failure is confirmed, replace the lambda probe. Thus, all the most important functions of the vehicle will be maintained at the same level, which will guarantee the absence of further problems with the engine and other important elements car.

Sensor. Symptoms of malfunctioning of this device will make you think about replacing it. Because the first sign is a significant increase in gas mileage. The reasons for this behavior will be discussed below. And first, it's worth talking a little about the history of the creation of this device, as well as about its principles of operation.

The need for an oxygen sensor

And now about what an oxygen sensor is needed for in a car. Its symptoms will be discussed later. When burning any fuel, oxygen must be available. The combustion process cannot take place without this gas. Therefore, oxygen must enter the combustion chambers. As you know, a fuel mixture is a combination of gasoline and air. If you pour pure gasoline into the combustion chambers, then the engine will simply not work. By how much oxygen remains in the exhaust system, we can say how well the air-fuel mixture burns in the engine cylinders. It is to measure the amount of oxygen that a lambda probe is needed.

A bit of history

At the end of the 60s, for the first time, auto designers began to try to install these sensors on cars. The very first oxygen sensors were installed in Volvo cars. also called a lambda probe. The fact is that there is a letter "lambda" in the Greek alphabet. And if you turn to the reference literature on internal combustion engines, you can see that this letter designates the excess air ratio in the fuel mixture. And this parameter allows you to measure

Principle of operation

The oxygen sensor is installed exclusively on injection vehicles that use electronic engine control units. The signal generated by it is fed to the control unit. This signal is used by the microcontroller in order to produce correct adjustment mixture formation. It regulates the air supply to the combustion chambers. Of course, the quality of the mixture is affected not only by the signal from the oxygen sensor, but also from most other devices that measure the load on the engine, its rpm, as well as the speed of the car, and so on. Often two lambda probes are installed in cars. One is a worker and the other is for correction. They are installed before and after the collector. Pay attention to the fact that the lambda probe, which is mounted after the collector, has additional forced heating. Before cleaning the oxygen sensor, be sure to read the manufacturer's requirements.

Working conditions of the lambda probe

It is also worth considering that the most effective functioning of this sensor occurs at temperatures from 300 degrees and above. It is for this purpose that electric heater... It allows the oxygen sensor to function normally while the engine is cold. The sensing element of the sensor must be located directly in the exhaust gas stream. So that its electrode, located on the outside, is necessarily washed with a stream. The inner electrode must be placed directly in the atmospheric air. Of course, the oxygen content is different. And between these two electrodes, a certain potential difference begins to form. A maximum voltage of 1 volt may appear at the output. It is this voltage that is applied to the electronic unit management. That, in turn, analyzes its signal, then, according to the fuel map embedded in it, increases or decreases the opening time of the injectors, changes the air supply to the rail.

Broadband

There is such a device as a broadband sensor (the UAZ "Patriot" has the same as any other car) sensors, which change the operating mode of the engine. The difference between a conventional and such a device is quite large. The fact is that they have completely different principles of functioning and sensitive parts. And broadband lambda probes are more informative, and this is important for cases when the engine is operating in non-standard modes. Consequently, the richer the information, the more accurate settings will be made by the electronic control unit.

How to identify a breakdown

It should be noted that oxygen sensors affect the functioning of the motor very strongly. If suddenly the lambda probe orders to live long, then the engine, most likely, will not work. When a lambda probe breaks down, no signal is generated at the output, or it changes in an unpredictable manner. Of course, this behavior will greatly complicate your daily life. The sensor can fail literally at any minute. For this reason, cars are equipped with certain functions that allow you to start the engine and also get to the workshop, even if the oxygen sensor is faulty.

Emergency firmware

The fact is that when the electronic control unit sees a breakdown of the lambda probe, it starts working not according to the firmware that is included in it by default, but according to the emergency one. In this case, mixture formation occurs according to data obtained from other sensors. Only the oxygen sensor is not involved in this process. The driver will notice the signs of malfunction of this device immediately. Unfortunately, the mixture is too lean, as the percentage of gasoline is higher than necessary. This ensures that the engine does not stall. But if you increase the air supply, then the chances are high that the engine will stall. However, as a warning on most vehicles, the dashboard Check Engine lamp, which signals about the literal translation of this inscription - "Check the engine". But even without it, you can determine the breakdown of the lambda probe. The fact is that the fuel consumption increases significantly compared to the normal mode.

Conclusion

Now you know what an oxygen sensor (lambda probe) is, what properties and features it has. In conclusion, I would like to mention that this element is very picky about how it is installed. Make sure that there are no gaps between the sensor housing and the collector, otherwise it will lead to premature exit failure of the device. In addition, during operation, the sensor will send incorrect information to the control unit.