Modern engines, as a rule, are equipped with injection engines with an electronic control unit that controls the operation of the power unit. For this, he relies on the readings of many sensors. Some of them are located in an accessible place, which greatly simplifies the replacement of a defective part. However, not in every case it is rational to replace the sensor, and then do-it-yourself catalyst fooling is carried out, the circuit of which is not very difficult to understand.
This is a lambda probe. In another way, it is also called an oxygen sensor, which is installed in the exhaust system. About why this is done, read on.
Problem
So that the car does not spoil the environment with its exhaust gases, an environmental standard was invented that regulates the content of harmful substances in the exhaust system. It began to operate in many European countries since 1988 (Euro-0). It is updated periodically, and outdated requirements are replaced by new ones. Currently, Euro-6 is operating.
These requirements have forced car manufacturers to build additional devices, one of which is a catalyst. Its task is to reduce the amount of nitrogen and carbon in the exhaust gases. In most cases, this is achieved by changing the chemical composition. In this case, a lambda probe must be present. Do-it-yourself catalyst blending, its circuit is very simple.
Since a faulty catalyst is very expensive, one effective method was invented that allows to some extent solve the problem at minimal cost.
Oxygen Sensor Function
To understand the need for a trick, it will not hurt to find out how the lambda probe works. Many instead of this sensor put various imitating devices, but in reality it is not always possible to achieve the desired result. For complete combustion of the air-fuel mixture, the optimal proportions of fuel and air are necessary - 1: 14.7. Using DMRV ECU (electronic control unit, in another way - the controller) "understands" how much air enters the cylinders and, depending on this, regulates the flow of fuel through the nozzles.
However, the controller is not aware of how exactly the fuel burns, and therefore a lambda probe is installed that is installed on the exhaust system. In some cases, it is replaced by a fake catalyst sensor. The role of the sensor is to determine the amount of oxygen remaining after burning the fuel mixture and sending data to the computer.
The computer, depending on the situation, takes appropriate measures:
- A small amount of oxygen indicates a poor mixture, so the fuel supply is increased to equal the norm.
- With a large amount of oxygen, which indicates a rich mixture, the controller, on the contrary, reduces the fuel supply.
- In case of incorrect signals from the sensor, or their absence, the system starts to work in emergency mode, which is laid down by the program.
Since at the given moment the requirements of Euro-6 have entered into force, then on most cars there are already not one, but two elements. One of them is installed in front of the catalyst, and the other after it. Often it is on this sensor that the catalyst blende is placed with your own hands, a diagram of which will be given later in the text. The controller takes readings from both lambda probes, which allows more accurate control of the fuel supply.
Catalyst failure
There are a number of signs by which you can judge the malfunction of the catalyst and begin to draw the appropriate conclusions. They can be:
- the car cannot start up or stall immediately;
- poor acceleration, while the engine is gaining momentum slowly;
- increased fuel consumption, but this symptom may indicate a malfunction of the nozzles;
- the exhaust color takes on a bluish tint with an unpleasant odor;
- the presence of metallic sound during acceleration;
- Check Engine indicator on the dashboard.
In some cases, when the Check Engine lights up on the dashboard, error P0420 may be displayed during computer diagnostics . In many ways, this indicates a catalyst, although the problem may be different.
Options for solving the problem
If you find a catalyst malfunction, you can use one of the effective ways to solve the problem. This allows you to significantly save on the purchase of new equipment. There are three ways to trick an ECU:
- installation of a mechanical blende;
- installation of electronic blende (emulator lambda probe);
- flashing the computer.
Consider each of these techniques in more detail.
Mechanical way
The technique consists in using a metal spacer, or sleeve, which is placed between the oxygen sensor and the exhaust pipe. Anyone who has some degree of turning skills can make a blende on their own. For the manufacture of parts taken bronze or heat-resistant steel. In addition, you need a blueprint for the trick itself, which is easy to find, since many have a computer. In his absence, you can take the help of friends or acquaintances.
At the end of the sleeve there is a small hole with a diameter of 2 mm for the passage of exhaust gases. Interestingly, do-it-yourself catalyst fooling is quite easy. Its scheme provides for the presence inside the ceramic chips with a catalytic coating.
The whole point is as follows. Exhaust gases first enter the sleeve and pass through a ceramic filler. The result is a chemical reaction, which reduces the concentration of carbon monoxide and hydrocarbon (CO and CH). After that, the gases reach the oxygen sensor, which transmits normal values ββto the computer.
From a constructive point of view, a snag is the same catalyst, only in a much smaller size. To install it, it is enough to follow a simple instruction:
- Remove the β-β terminal from the battery.
- Get to the location of the second oxygen sensor (which is after the catalyst), if necessary, by partial disassembly.
- Disconnect the connector, unscrew the lambda probe with a 22 key and install the sleeve.
- Screw the oxygen sensor into the snag and connect the connector.
As you can see, installing a blende on a catalyst is not as complicated as it might seem at first glance. It is more convenient to do all the work on a pit or lift.
Electronic way
Electronic blende also gives a positive result, and anyone who is friends with a soldering iron will be able to collect it. To make the simplest part, you can not do without:
- non-polar capacitor with a capacity of 1 ΞΌF;
- resistor with a resistance of 1 megohm;
- soldering iron, knife, nippers;
- solder;
- rosin.
The electronic blende is mounted on the wires of the oxygen sensor. On some vehicles, the lambda probe connector is located in the passenger compartment between the front seats. For others, it can be found in the engine compartment, while for others it is again located in the cabin under a torpedo.
Before installing the emulator lambda probe, you must disconnect the negative terminal of the battery. Further actions can be performed according to the scheme:
- In the area in front of the connector, remove some insulation.
- Cut off the black wire, and connect the gap with a resistor (solder).
- Connect the capacitor with one contact to the gray wire, and the other with the black, but after the resistor (closer to the connector).
- Insulate the wires or do this after checking.
- In conclusion, it remains to start the engine and see if the Check Engine indicator lights up in any operating mode. You may need to ride a bit.
Apparently, there is nothing complicated here either. There is only one caveat: this method may not work on some cars. Resistors and capacitors must be selected with a specific rating. And if the oxygen sensor that is in front of the catalyst is faulty, then it does not make sense to βmisleadβ the controller. In addition, electronic deception of the catalyst can cause serious material damage to the car, as its design is improved from year to year. Therefore, it is better to do with regular parts instead of failed ones.
Flashing ECU
This method is a cardinal solution to the problem. The point is to exclude from the "field of view" of the computer an oxygen sensor after the catalyst. In this case, the computer will operate with data from the first lambda probe, and emergency mode will not turn on.
If mechanical catalyst blending can bear fruit, then this method has a significant drawback: it is impossible to find the correct factory firmware. And you can use third-party funds only at your own risk, since there is a risk of spoiling the engine's performance. To solve this issue, you will have to look for an excellent specialist, and for money the costs can be compared with the cost of the original part. So is it worth it ?!