Vacuum leaks, oxygen sensor failure, and catalytic converter efficiency faults can cause the Check Engine Light to illuminate.
Average mileage: 74,598 (31,000–131,000)
Exhaust & Emissions affected: 1.8L 4 Cylinder Turbo
17 people reported this problem
Engine check light on. Audi review noted oxygen sensor, another auto repair mentioned it may be some else which caused this to happen. Review turned up nothing. I now want an dedicated audi TT repair location other than the dealer to check problem. Any suggestions.
CEL on, replaced MAF CEL back on two days later! Common in German cars, same problem with Mercedes SLK 230 Kompressor. Never resolved after multiple repairs.