Emission control systemEmission control system  - Warning and indicator lamps - Instruments and warning/indicator lamps - Controls - Audi S5 Owner's Manual - Audi S5

If the warning lamp lights up continuously you should take your vehicle to a qualified workshop as soon as possible in order to have the fault rectified.

If the warning lamp flashes drive on at reduced speed and seek professional help in order to avoid damage to the catalytic converter.

For further information on the catalytic converter.