Table of contents: Unregulated catalytic converter ↓ Adjustable catalytic converter ↓
A relatively simple, but effective system, serves to reduce NOx content. A valve-controlled system removes a portion of the exhaust gas flow, depending on the engine load, and returns it back to the intake manifold.
Since the exhaust gas contains almost no combustible substances, this leads to a decrease in the temperature in the combustion chamber and, as a result, to a decrease in the NOx content.
This system is used in certain modifications of the Audi vehicle.
Unregulated catalytic converter
Thanks to the unregulated catalyst, it is possible to reduce the content of harmful substances in exhaust gases by up to 65%.
Adjustable catalytic converter
The adjustable catalyst deactivates about 90% of harmful substances. It is not the catalyst itself that is adjusted, but the fuel-air mixture. This ensures optimal operation of the catalyst. The composition of the mixture is determined by the lambda probe depending on the composition of the exhaust gases. Its operation is described in more detail below.
(The original material is located on the website: «AudiManual»)