Audi Repair: start and idle problem, catalytic converters, audi dealership

Question
Hey Jan,

I have an 2002 Audi a4 1.8t. i just got it like 6 months ago. At first when you started the car it would run a little rough and sputter a bit and after a while, it got to the point that sometimes it wouldn't start at all.It just kept stalling. It gives me random misfire codes and a bad CAT code. We took out the MAF and cleaned it, and for a couple days it was ok but then started all over again. the coils are ok and the wires seem fine. The car will run rough and sputter for like 40 seconds and then it quiets down and runs fine. An Audi dealership told me they didn't know and gave it back to me. Do you have any ideas that might lead me in the right direction. thanks alot.

Answer
SOunds like you Audi dealership doesn't want to spend the time troubleshhoting your problem.  What gas grade are you using?  You need to use premium gas in that engine.  Also bad catalytic converters are a more and more common problem, and this will affect the running of the engine.  If the cleaning of the MAF helped, perhaps the AMF is not a functional as it should be, it may be worth trying a new one. Also if the random misfire code is still present, the coil pack may be bad.  Let me know,  Jan