The inlet and outlet cones with branch pipes and mounting flanges, as well as heat reflectors holding the ceramic lining, are welded to the stainless steel body of the neutralizer. The entire internal volume of the body is occupied by a ceramic porous monolith - a catalyst, fixed by rings or a stainless steel mesh. The catalyst is a filter in which the entire inner and outer surface of the pores in contact with gases is covered with a very thin layer of an alloy that contains platinum, rhodium and palladium. The porous catalyst has a large surface area coated with this alloy of very expensive metals, which mainly determines the high price of catalytic converters.
A reaction takes place in the converter, as a result of which potentially hazardous hydrocarbons and carbon monoxide in the exhaust gases are converted into harmless gases and water vapor.
On all models with a converter, the fuel supply system is of a closed type, that is, based on the signal from the lambda sensor installed in the exhaust system, the control unit constantly optimizes the composition of the air-fuel mixture. Depending on the oxygen content in the exhaust gases, the lambda sensor induces a voltage of 0.1 V (high oxygen, lean mixture) up to 0.9 V (low oxygen, rich mixture). Based on this data, the engine control unit changes the opening time of the injectors and the ratio of fuel in the air-fuel mixture. In order for complete combustion of the combustible mixture to occur and there were no harmful substances in the exhaust gases, 1 part of fuel must fall on 14.7 weight parts of air.
The catalytic converter works effectively at a temperature of +300…+800°C.
Operating vehicles with a catalytic converter
The neutralizer is a reliable and simple device that does not require maintenance. In order for its service life to be maximum, the following requirements must be observed.
Do not use leaded gasoline in a vehicle equipped with a catalytic converter, as the lead will coat the precious metals in the catalyst grid, reducing their effectiveness and eventually damaging the converter.
Always keep the ignition and power systems in good condition.
Do not operate a vehicle with a faulty ignition system until the fault is corrected.
If the engine control warning lamp lights up while the engine is running, contact a service station as soon as possible. If the engine management system is damaged, then in addition to increasing fuel consumption and deteriorating the dynamic characteristics of the engine, the catalytic converter may fail.
Do not start the engine by towing.
Do not turn off the ignition at high engine speeds.
Do not use fuel and engine oil additives as they may contain substances that can damage the catalytic converter.
Do not drive the vehicle if blue smoke is emitted from the exhaust pipe.
After stopping the engine, the exhaust system continues to radiate heat for a long time, so you should avoid parking the car on grass and dry leaves.
Remember that the converter is fragile, so avoid shock when removing it or other elements of the exhaust system.
The service life of a catalytic converter on a well-adjusted car is 100-160 thousand kilometers of the car.
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