DIY oxygen sensor repair

In detail: do-it-yourself oxygen sensor repair from a real master for the site my.housecope.com.

All parts and assemblies of the car have their own service life. It can be long, short, but endless - never, so every element of the car needs to be replaced sooner or later. The lambda probe is no exception. Moreover, it fails, unfortunately, quite often, but it is not cheap, so it is not surprising that experienced motorists, bypassing the recommendations of the manufacturers, have found a way (and not even one) how to clean the lambda probe at home, that is, significantly reduce their costs for repairs. But first things first.

A lambda umbrella (also often called an oxygen sensor) is a special sensor-controller that measures (estimates) the amount of oxygen remaining in the unburned fuel mixture (exhaust gases) of a car, compares it with nominal values and sends the data obtained as a result of this comparison to control unit (CU) fuel system. The control unit, in turn, in order to optimize the composition of the combustible mixture, increases or decreases the volume of fuel supplied to the combustion chamber, thereby affecting the content of harmful substances in the exhaust gases, the dynamics of the car, the stability of the power plant and other characteristics.

Hence, it is obvious that if the oxygen sensor is faulty, that is, it sends incorrect information to the control unit, then the fuel / oxygen supply will be made with errors. As a result, the car will start to “eat” a lot, accelerate poorly, work unstably and pollute the environment (more than the accepted environmental standards allow). Such a situation can be prevented only by timely replacement of a failed sensor or cleaning it in cases where it is permissible - the sensor itself, its base are not damaged, and improper operation is provoked by contamination accumulated on it (lead deposits and soot).

Video (click to play).

The first step is to find this lambda probe. This can be done under the hood of your car in front of the catalyst. And in modern cars, two such sensors are installed - before and after the catalyst, so it is easiest to view them from the pit.

Once you find the lambda zotd (s) in your car, dismantle it (s) using a key of a suitable size.

Then move on to cleaning.

This method could be called one of the simplest and fastest, if not for the need for full / partial access to the ceramic-platinum base of the device, hidden behind a protective metal cap, which is not so easy to remove, given the impossibility of working with a hacksaw on metal , as it can damage the working base. What to do? - Use a lathe for this purpose: use a lathe at the very base of the lambda probe to cut off the protective cap near the thread with a cutter.

If you don't have such a machine, you can try using a file. Of course, you won't be able to remove the protective cap with it, but making windows (5 mm holes) in it is easy.

So, when access to the working rod of the lambda probe is provided, you can proceed directly to the procedure for cleaning it.

To do this, take at least 100 ml of phosphoric acid (its analogue: rust converter, flux / acid for soldering, etc.), pour it into a small glass container (glass, jar, glass, etc.), and then lower the core there clogged parts.

IMPORTANT: the entire device must not be immersed in phosphoric acid!

Wait 15-20 minutes, rinse the base of the part with clean water, leave to dry completely.If necessary, repeat the procedure until the black-brown core is metallic again.

If you did not succeed in cleaning the lambda probe in this way either from the second or the third attempt, try increasing the effect of an aggressive liquid with a brush: constantly wetting and smearing the base, you will very soon notice how the dirt will begin to disappear, returning the parts to their original shine.

By the way, if the work will be carried out on the lambda probe with the protective cap removed, then instead of a brush, you can use something larger, for example, an old toothbrush.

At the end of the cleaning work, it is again recommended to rinse the oxygen sensor thoroughly with clean water and dry it thoroughly.

If the cap was removed, then before installing the part, it is returned to its place using argon welding.

When applying this method, you need to remember:

orthophosphoric acid (and its analogs including) is a dangerous chemical, therefore it is necessary to work with them, observing all safety rules and excluding its contact with the eyes and inside the body;
if the lambda probe is heavily clogged, then the named 15-20 minutes for its complete cleaning may not be enough, therefore, in especially advanced cases, the time of exposure to the acid on the core should be increased to 1-3 hours, and sometimes the whole night (at least 8 hours) ;
to check the effectiveness of such repairs, as a rule, it takes some time, only it will enable the driver to evaluate the "behavior" of the car and measure the fuel consumption, the exception is the Check Engine error lit up on the instrument panel, it is an indisputable sign that you will reanimate a clogged lambda probe failed;
if in your car the protective cap of the oxygen sensor has a double shell (two layers), most likely you will not be able to cut it with a file, so the only way to clean the core of such a lambda probe is to soak it in acid together with a protective element.

To implement it, you will need the same phosphoric acid and a gas burner or stove. If the choice falls on the latter, it is better to use the smallest burner (it will be more convenient): remove the lid from it, turn it over and put it, slightly shifting to the side, so that it protects (closes) the gas pipe from possible acid ingress there.

Then everything is simple: light a fire, dip the oxygen sensor core in acid and heat thoroughly over this fire. When the acid starts to boil and splatter, a blue-green salt will start to show through on the surface of the sensor.

Wait until the aggressive liquid boils down completely, rinse the part with clean water, dip it again in phosphoric acid and on fire ... - repeat these steps until the lambda probe shines clean (in our case, it took about 15 minutes). Before installation, the threads of the oxygen sensor should be lubricated with graphite grease (so that it does not burn).

Only then can the part be returned to its place.

As practice shows, the oxygen sensor, free from soot and soot, begins to work correctly again only in 1-2 percent of cases, so it is not worthwhile to rely heavily on the methods described above, cleaning the lambda probe at home with your own hands, especially if the mileage exceeds 100 thousand kilometers, however, in order to save your budget, it is still worth trying to revive this device.

Once you find the lambda zotd (s) in your car, dismantle it (s) using a key of a suitable size.

Then move on to cleaning.

If you don't have such a machine, you can try using a file. Of course, you won't be able to remove the protective cap with it, but making windows (5 mm holes) in it is easy.

So, when access to the working rod of the lambda probe is provided, you can proceed directly to the procedure for cleaning it.

IMPORTANT: the entire device must not be immersed in phosphoric acid!

Wait 15-20 minutes, rinse the base of the part with clean water, leave to dry completely. If necessary, repeat the procedure until the black-brown core is metallic again.

By the way, if the work will be carried out on the lambda probe with the protective cap removed, then instead of a brush, you can use something larger, for example, an old toothbrush.

At the end of the cleaning work, it is again recommended to rinse the oxygen sensor thoroughly with clean water and dry it thoroughly.

If the cap was removed, then before installing the part, it is returned to its place using argon welding.

When applying this method, you need to remember:

orthophosphoric acid (and its analogs including) is a dangerous chemical, therefore it is necessary to work with them, observing all safety rules and excluding its contact with the eyes and inside the body;
if the lambda probe is heavily clogged, then the named 15-20 minutes for its complete cleaning may not be enough, therefore, in especially advanced cases, the time of exposure to the acid on the core should be increased to 1-3 hours, and sometimes the whole night (at least 8 hours) ;
to check the effectiveness of such repairs, as a rule, it takes some time, only it will enable the driver to evaluate the "behavior" of the car and measure the fuel consumption, the exception is the Check Engine error lit up on the instrument panel, it is an indisputable sign that you will reanimate a clogged lambda probe failed;
if in your car the protective cap of the oxygen sensor has a double shell (two layers), most likely you will not be able to cut it with a file, so the only way to clean the core of such a lambda probe is to soak it in acid together with a protective element.

Read also: DIY fumitox repair

Apply a small amount of phosphoric acid to the ceramic rod of the lambda probe. In this case, you can use a thin paint brush; the sensor must not be completely immersed in acid. A dirty rod is usually black or brown and should turn gray after cleaning. The applied acid does not come into contact with the dirt immediately, usually it takes about 20 minutes. After cleaning, the lambda probe is rinsed under running water and dried. The protective cap can only be welded into place using argon welding. If such a device is not at hand, then the protective cap is not dismantled before cleaning the oxygen sensor. Using a file, it is necessary to make two small windows in it and rinse the rods indiscriminately.After installing the cleaned lambda probe in place, it is necessary to test its condition. This check is carried out using a computer scanner. It is worth noting that cleaning the oxygen sensor is only an extreme method, which can only be resorted to if abnormalities in the operation of this unit are detected. The lambda probe, also known as the oxygen sensor, allows you to estimate the amount of free oxygen remaining in the exhaust gases. Its readings allow the ECU to correct the composition of the mixture. Oxygen sensor malfunctions may cause the engine to malfunction. Before replacing it, try do it yourself oxygen sensor repair.First, let's figure out where and what is a lambda probe for?: Hello everyone! My name is Mikhail, now I'll tell you a story about how I managed to exchange a dvenashka for a 2010 Camry. It all started with the fact that I was wildly annoyed by the breakdowns of the two, like nothing serious broke down, but the little things, damn it, so many things that really started to enrage. Here the idea was born that it was time to change the car to a foreign car. The choice fell on the tayet Camry of the tenths.The sensor reacts to the difference between the oxygen level in the exhaust gases and in the atmosphere, producing a corresponding potential difference at the output. Since a certain amount of oxygen must be present in the exhaust for normal afterburning of CO and CH on the catalyst, for more accurate regulation, use second oxygen sensorlocated behind the catalyst.The first 5-7 minutes after starting the engine, the ECU corrects the composition of the mixture based on the readings of other sensors and according to the averaged parameters. After this time, when the oxygen sensor has warmed up to operating temperature, then the ECU connects its parameters to the general calculation formula.Oxygen sensor error could be caused by a malfunction of the heating circuit.As a result, the sensor will not have time to warm up in the allotted time, which means that incorrect oxygen sensor signals... The fuel mixture will be inappropriate, which negatively affects the operation of the engine (high fuel consumption, idling speed floats, the car does not drive). As soon as the oxygen sensor warms up to operating temperature, then all symptoms disappear.Resource of the oxygen sensor VAZ can reach 100-150 thousand km., but the service replacement of the oxygen sensor in the top ten should take place in the range of 60-80 thousand km.A common cause of malfunctions is carbon deposits that impede oxygen capture and thus distort the output signal.
Image - DIY oxygen sensor repair

Therefore, to restore oxygen sensor you need to clean the platinum electrodes on the ceramic rod from carbon deposits.
It is impossible to clean carbon deposits by mechanical means, since this method will damage the metal spraying. It remains only to resort to the help of chemistry.

We open the sensor, for this we saw off first the first and then the second protective caps. Objective: to reach a white ceramic rod with carbon deposits of the same color.

Phosphoric acid is required to clean the sensor rod from carbon deposits, which may be part of the rust converter. Before using cleaning products, make sure they do not leave behind a protective layer.

We immerse our sensor in the cleaner for 20 minutes. During this time, the liquid will begin to grow cloudy, and the carbon deposits will go off (use of a soft brush is allowed).

Heating also allows you to get rid of carbon deposits, especially if you sharply cool the rod after heating. The temperature difference forces the soot to crack and fall off like a shell.

We heat the ceramic rod a couple of times over an open fire.

After cleaning, we grab the caps on several points of the semi-automatic kempi welding.

Oxygen sensor VAZ 2110, as sensors of foreign cars have a similar structure, therefore such cleaning the lambda probe suitable for every car enthusiast.

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Did you manage to repair the oxygen sensor of the car?

Most modern cars have special electronic control systems. They save fuel consumption and ensure optimum engine performance. One of the integral elements of the exhaust system is the lambda probe. If it breaks down, the engine starts to work in emergency mode. Can you fix the problem yourself?

The sensor records the amount of oxygen in the vehicle exhaust and transmits it to the control panel. Depending on the readings of the probe, the computer regulates the level of enrichment of the mixture that is supplied to the combustion chamber. Most models have two probes, one in front of the catalyst and one behind it. During operation, oxygen sensors fail; manufacturers recommend cleaning the devices every 30 thousand kilometers.

Many motorists forget about such recommendations and face a problem after the warning sign on the panel lights up. Most often, the lambda probe cannot be repaired. The cost of the device is rather big, and its replacement is always very inappropriate. Craftsmen have found a way out of this unpleasant situation.They suggest using a special automotive trick that will allow the engine to run normally and disable the Check Engine alarm.

Tip: Do not completely disable or block one of the sensors, this will not solve the problem and will only lead to increased fuel consumption and unstable engine idling.

There are three ways to make a snag for the on-board computer with your own hands:

install a mechanical bushing;
connect a simple electronic circuit;
flashing the controller.

Each of the methods quite effectively solves the problem of a failed sensor and returns the engine to its normal state.

To trick the controller, you need to install a metal bushing between the exhaust pipe and the lambda probe. To make a part you will need:

metal blank;
processing machine;
screwdriver;
a set of keys.

Tip: We recommend using a workpiece made of bronze or heat-resistant steel - these metals can withstand high temperatures and not deform.

Bronze mechanical snag can be made manually or ordered by a specialist

You can make a part even without special work skills, the main thing is to have a good lathe. As a last resort, you can order its production from a familiar specialist.

The shape and dimensions of the sleeve are shown in the drawing.

The part must exactly match the diagram in shape and size

To install a mechanical plug, do the following:

To install a mechanical trick, the sensor must be unscrewed

A part made exactly according to the scheme is screwed onto the lambda probe

After starting the engine, the Check Engine signal should go out. This moves the sensor slightly away from the exhaust stream. The mechanical snag-screw is suitable for most car models, the main thing is that the sensor is screwed into the body.

Since the controller receives electronic signals that come to it from the lambda probe, you can put a special blende circuit. It connects to the wires that go from the sensor to the connector. The installation location is different for different models: it can be a central tunnel between the seats, a torpedo or the engine compartment. To make an electronic circuit, prepare the following materials:

soldering iron with a fine tip;
capacitor with a capacity of 1 μF;
1 MΩ resistor;
knife;
rosin.

Electronic snag must be correctly assembled according to the wiring diagram

Disconnect the negative terminal before starting work. All connections must be well insulated. The best option would be to place the circuit in a plastic mold and fill everything with epoxy glue.

All electronic blende connections must be well insulated.

On sale you can find ready-made electronic tricks. They use a small microprocessor that analyzes the signal of the first sensor, processes it and generates the necessary indicators for the on-board computer. Such devices are easy to connect, but they will cost more than a homemade circuit.

Another variant of the trick is the flashing of the on-board computer itself. By changing the algorithm of the device, you block the processing of signals from the second lambda probe. The danger of this method is that if it is done incorrectly, it will be difficult to restore the previous operation of the computer. The original factory firmware is very difficult to obtain and the cost is quite high. Therefore, such work should be entrusted only to an experienced specialist whom you know personally.When installing tricks, it is worth taking into account that all work is carried out at your own peril and risk. If such devices are installed incorrectly, the following malfunctions may occur:

Malfunction of the engine due to improper injection adjustment by the on-board computer.

Damage to the wiring and controller due to an incorrectly soldered circuit.

Errors in the operation of the on-board computer.

Damage to sensors.

Work with any kind of electronics must be done very carefully. Even the slightest inaccuracy can lead to damage, so you need to follow the instructions carefully.Tip: You should not order trickery on the Internet on dubious sites. Most of them do not work well and will not bring the expected result.Deception of lambda probes is practiced by many motorists. Such devices save money on replacing failed sensors. It is important to correctly make a snag and install it so that the latter does not appear negative for the on-board computer or engine.Date of publication: December 20, 2016.The lambda probe is an O concentration sensor₂ (or, more simply, an oxygen sensor), which allows you to estimate the amount of unburned oxygen contained in the exhaust gases. These indicators are extremely important, since due to the maintenance of certain proportions of fuel and air, the most efficient combustion of the air-fuel mixture occurs. The best ratio is considered to be 14.7 parts of oxygen per 1 part of gasoline. If this ratio is violated, then the mixture will be lean or, conversely, rich, which, in turn, will affect fuel consumption and engine power.Although outwardly the oxygen sensor does not look like a "vital" part, it performs a very important function, so any malfunction of the lambda probe, the "symptoms" of which we will consider, must be immediately corrected.According to statistics, oxygen sensors fail gradually, so you can identify its malfunction if you pay attention to the following "symptoms" in time:

The idle speed began to fall or "float".

The car jerks, and after starting the engine, you hear claps uncharacteristic of the engine.

The engine power has decreased and a delayed reaction is observed when the gas pedal is pressed.

The engine overheats a lot and fuel consumption has increased.

The smell in the exhaust pipe has changed (the exhaust gases have become more toxic).

As a result of a failed sensor, the quality of the fuel mixture entering the combustion chamber deteriorates, which disrupts the smooth operation of the engine. There can be many reasons for this:

Incorrect operation of the heating circuit or reduced sensitivity of the sensor tip.

Low-quality fuel with a high content of iron, lead, oil decay particles and other harmful impurities. All of these substances adhere to the platinum electrodes, causing the sensor to malfunction.

Problems with the lambda probe heating system. If the heating has ceased to function as needed, then the oxygen sensor will give inaccurate data.

Overheating of the regulator body. This happens if the ignition timing is incorrectly set.

Worn oil scraper rings. In this case, engine fluid enters the exhaust pipe, which acts on the lambda probe.

If the engine is started repeatedly.

The use of sealants (especially silicone) for the installation of lambda probes.

The level of compression in the engine cylinders is violated. In this case, the combustible mixture burns unevenly.

Clogged petrol injectors in the engine.

If you notice that the lambda probe is not working, the symptoms should not be ignored, as otherwise you will provide yourself with many problems with the car. The fact is that most modern cars are equipped with an emergency blocking unit, which can be triggered at the most unfortunate moment. However, the impossibility of further movement is not the worst thing. If the sensor is depressurized, the injection system will fail and you will have to pay for expensive repairs of a more serious unit.Therefore, it is recommended to periodically check the status of the lambda probe. You can do this yourself.Usually, a lambda probe is diagnosed using a voltmeter and an ohmmeter or multimeter, which replaces both of these testers at once. To check the filament coil of the regulator, it is necessary to disconnect pins 3 and 4 of the connector from the block (usually brown and white wires) and connect the ends of the tester to their terminals. If the resistance of the coil is at least 5 ohms, then this is a good sign.Also, checking the lambda probe with a multimeter allows you to find out the sensitivity of the oxygen sensor tip. To find out the thermoelectric parameters of an element, it is necessary to turn on and warm up the engine to 70-80 degrees. Thereafter:

Bring the engine speed to 3000 and hold this indicator for 3 minutes to warm up the sensor.

Connect the negative probe of the tester (signal wire) to the ground of the car, and the second to the output of the lambda probe.

Check the tester reading, the data should vary from 0.2 to 1 V and update up to 10 times per second.

Press the accelerator pedal sharply and release it, if the multimeter shows a value of 1 V and then drops sharply to zero, then the lambda probe is in order. If the data on the tester does not jump when the pedal is pressed and released, and the readings are about 0.4 - 0.5 V, this indicates the need to replace the sensor.

If there is no voltage at all, then, most likely, the cause of the malfunction lies in the wiring, so "ring" with a multimeter all the wires that go from the ignition switch to the relay.Healthy! To more accurately clarify the characteristics of the sensitivity of the lambda probe, you will need professional equipment - an oscilloscope.If your car is equipped with a "smart" on-board system, then pay attention to the "Check Engine" signal, which can give the following errors:

0130 - indicates that the sensor is giving a wrong signal.

0131 - very weak sensor signal.

0133 - lambda is responding slowly.

0134 - there is no response at all.

0135 - malfunction of the lambda heater.

0136 - grounding of the second sensor is shorted.

0137 - the second sensor gives a very low signal.

0138 - too high signal of the second lambda.

0140 - probe breakage.

1102 - it is impossible to read the indicators, since the resistance of the element is too low or is completely absent.

However, before you check the oxygen sensor lambda probe (video of this process is presented below) using a special tester, pay attention to its appearance. If substances that interfere with its full-fledged work are adhered to it, then it may be possible to limit ourselves to repairing this element.