Audi A4, S4
since 2000 release
Repair and operation of the car
Audi A4, S4
+ Governing bodies and methods of safe operation
+ Current leaving and service
+ Cooling systems, heating and air conditioner
- Power supply systems, release and decrease in toxicity of the fulfilled gases
+ Power supply systems of petrol and diesel engines
+ System of injection of fuel of the petrol engine
+ System of injection of fuel of the diesel engine
- Systems of release and decrease in toxicity of the fulfilled gases. Turbocompressor
Removal and installation of system of release. Replacement of the central, additional muffler, trailer pipe
Correction of laying of system of release / trailer pipe
Systems of decrease in toxicity of release - the general information
Removal and installation of the catalytic converter and lambda probes
Turbocompressor - the general information and precautionary measures
Interkuler - the general information
+ Systems of electric equipment of the engine
+ Manual box of gear shifting
+ Automatic transmission
+ Coupling, power shafts and differential
+ Brake system
+ Suspension bracket and steering
+ Onboard electric equipment
The catalytic converter has the central ceramic part of a cellular design-3-covered with a carrier layer. On a layer of the carrier there are salts of precious metals operating as converters. The catalytic converter is fixed in the case-1-by means of the insulating basic layer-2-compensating at the same time thermal expansions of the catalytic converter (address to the illustration Arrangement of Elements of System of Injection in a compartment of the diesel engine of 2.5 l).
To reduce harmful emissions by means of the catalytic converter, systems of injection has to dose precisely amount of the injectable fuel necessary for combustion. The lambda probe is in a reception pipe in front of the catalytic converter and is washed by a stream of the fulfilled gases. The lambda probe represents the electronic sensor measuring the content of oxygen in final gases and representing its type of fluctuations of tension. Information from a lambda probe is transferred to the control unit of system of injection. The received value allows to regulate composition of air-petrol mix. On the one hand it is necessary as service conditions (idling, full gas), on the other hand, constantly change as optimum reburning of fuel in the catalytic converter happens only in this case if final gases contain enough fuel.
That in the catalytic converter there was a fuel reburning, it is necessary to have temperature of 300 - 800 °C. For this purpose the bigger content of fuel in mix, than is necessary for pure burning.
The catalytic converter of the petrol engine represents the so-called three-functional device. In adjustable process of transformation oxidation of carbon monoxide (WITH) and hydrocarbon (NANOSECOND), and also reduction of concentration of nitrogen oxides (NOx) is carried out.
Security measures for an exception of damages of the catalytic converter
For an exception of damages a lambda probe and the catalytic converter it is necessary to fulfill the following requirements:
Petrol and diesel engines