Catalytic Converter: Description and Operation

Exhaust System / Emission Control

The exhaust system not only ensures that pollutants are cleaned from combustion exhaust gases, it also has a significant effect on the acoustics of the vehicle. The main function of the exhaust system is after-treatment of the exhaust gas.

Cayenne Turbo exhaust system

There are a number of differences in the exhaust system of the V8 turbo engine compared with the exhaust system of the V8 naturally aspirated engine. For example, the pipes of the twin-branch exhaust system of the Cayenne Turbo have larger cross-sections compared with the exhaust system of the V8 naturally aspirated engine and there is also no branch coupling connection. The larger cross-sections result in comparable exhaust gas speeds in both exhaust systems.

Twin-branch exhaust system










Exhaust manifold / Turbocharger / Catalytic converter

The exhaust manifolds of the Cayenne Turbo are air-gap insulated. The water-cooled turbochargers with wastegate valve are flanged on.

The cylinder bank-specific LSU oxygen sensors ahead of the catalytic converter and LSF oxygen sensors behind the catalytic converter signal the exhaust gas composition to the DME control unit. The DME control unit can then use this information for targeted intervention in bank-specific mixture control.

This ensures that the strictest emission standards are satisfied or exceeded.