Modern cars are equipped with catalysts, which are needed to purify exhaust gases from harmful substances contained in unburned fuel. Replacing a failed catalyst can be quite expensive, so some car owners may think about removing it.
Why do you need a catalyst
Environmental requirements for the cleanliness of car exhaust are constantly increasing. This leads to a systematic complication of the design of machines. Previously, the products of fuel combustion immediately fell into the exhaust manifold, and from there they were discharged into the atmosphere through the exhaust pipe. The gases are now analyzed by several electronic sensors and burned out in the catalyst cells.
The first sensor is located in front of the catalyst - it determines how much fuel could not be burned in the cylinders. If there is too much of it, a signal is sent to the engine control unit, which reduces the fuel supply. The gases enter the red-hot honeycomb and finally burn out. The quality of the catalyst is checked by a sensor at the outlet. This is true for engines complying with the Euro-3 standard and above.
How to remove the catalyst
Some car owners believe that this device reduces engine power and that removing it will provide additional horsepower. This is a misconception - removing the catalyst can increase the exhaust sound, but the car will not go faster after that. An improvement in acceleration dynamics can be observed only in one case - if the cells were clogged with combustion products, which led to a drop in engine power. In such a situation, removing the catalyst simply returns the car to its passport characteristics.
But there are more compelling reasons for removing it. The life of the catalyst is limited. It is constantly exposed to high temperatures, which eventually leads to its destruction. The use of low-quality fuel speeds up this process. If the decaying catalyst is not removed in time, its particles can enter the engine. This may necessitate a major overhaul or even replacement of the engine.
Of course, the most reasonable solution in such a situation is to replace the catalyst with a new one. But this is quite expensive. Therefore, the car owner may be tempted to simply dismantle the device.
If you remove the catalyst from the exhaust system, you will run into a number of problems. Sensors that analyze the composition of gases will not be able to work properly. At best, they will give an error on the dashboard, but in some cases the car will not even start. Excess fuel that was burned out in the catalyst will burn in the exhaust pipe, which can lead to its rapid burnout.
If you nevertheless decide to completely abandon the catalyst, you will need to carry out certain work. Special flame arresters should be installed to protect the exhaust system. The engine control unit needs to be reflashed, teaching it to work in new conditions.
On engines of "Euro-3" standard and above, you will need to trick the oxygen sensor at the outlet of the collector. You cannot simply delete it - the ECU will generate an error, and the engine will go into emergency operation. The easiest way is the so-called "chiping", when the control unit is programmatically prohibited from interrogating the second sensor. Unfortunately, this method does not work for everyone.
car models.
Another option is to use a spacer that is screwed between the sensor and its seat. As a result, the probe will be outside the main stream of exhaust gases, and its readings will be close to normal.
There is also a more complicated option - the use of electronic "tricks". To do this, some changes are made to the electrical circuit of the sensor by soldering a capacitor of a certain capacity. As a result, the signal transmitted from the probe is modified, and the computer considers that the catalyst is still installed.
