First, don't flame me, I've searched and read the plentiful posts on this error.

I have an '01 A4 1.8T Q that I bought about about 2 weeks ago. I first got the "check engine" light when I picked it up after getting inspected (prior to purchase). The next day (shop was closed when I picked it up) I took the car back and noticed that the light was no longer lit. So I notified the mechanic and said I'd be back if it came back on.

So today I was on the road and the check engine light came back on. I immediately got the error code read - P0171 error. Well, after stopping by the shop and booking a checkup, the light went off again.

I'm guessing this would most likely be a dirty/faulty MAF sensor, rather than a leak. Should I still have the car checked (It was inspect less than 2 weeks ago) or just go ahead and have the sensor cleaned/replaced?

 

First check for vacuum leaks.