I recently had my 98' audi a4 quatro in the shop. They put in a new radiator and i was curious if that could affect the long term fuel trim. not to long ago i had some other work done on my audi and within a week something else was wrong. this is the second time that the same mechanic "fixed" my audi and was just wondering if he could have done something to mess with the long term fuel trim. both banks 1 and 2 are registering a LTFT too rich. Any feedback would be great.

Thanks

 

If it was only on one bank I'd suspect that bank's primary O2 sensor. Being both banks you could have two bad ones or possibly a bad MAF. Can you post the actual codes stored in the ECU? That'll help a lot in helping you figure out the issue.