1999 Audi A4 Quattro Q&A
1999 Audi A4 Quattro Question: What can cause my check engine light to come on?
The check engine light indicates that the computer has detected a malfunction in the engine/emission control system and has diagnostic codes and data stored which would be essential in diagnosing the problem. A technician with a scanner could access the diagnostic codes and data and then be able to give you a diagnosis. If you want to find a specialist, here's a directory link for you: https://repairpal.com/directory?address=30236&car_brand_names=Audi - Superbob