Catalytic converterCatalytic converter  - Your vehicle and the environment - Driving tips - Audi S5 Owner's Manual - Audi S5

The vehicle must only be used with unleaded petrol, otherwise the catalytic converter will be destroyed.

Never run the tank completely dry. The irregular fuel supply can cause misfiring, which would allow unburnt fuel to enter the exhaust system, which could cause overheating and damage the catalytic converter.

Х Because of the high temperatures which can occur in the catalytic converter, do not park the vehicle where the catalytic converter can come into contact with flammable materials under the car (e.g. on grass or at the forest edge). - Fire hazard!
Х Do not apply any underseal agents in the area around the exhaust system - fire hazard!