Ight, this is the deal. I just did an darintake on my 02 a6 2.7t.About two hours of driving, the check engine light came on. Still drove the car for alittle ended up running a g35x. Raced him twice was, close both times, and then about ten minutes after the race the check engine light shut off. After the light turned off my car seemed to run twice as better then before. Both turbos ranperfectly and were spooling really nice clean and loud.Ifanyone has any idea what happed please let me know.

 

I have a similar issue. My engine light is on often, some days my car flys other days it's a little sluggish. Sometimes it's both in the same day. Took to audi mechanic and the code reads issue with cat converter. he suggested replacing it. Have not replaced yet. Althought I have not had any issues yet on a cool day/ night - below 65 degrees out. Hoping to find some answers as well. Any insight would be greatly appreciated.

2001 A6 2.7T, Blk on Blk, exhaust, chipped, lowered, RS rims

 

Had a similar problem. Code states -resistance to high bank1 and 2- O2 sensors could be replaced but mechanic said if it shuts off then the ECU fixed the problem(no longer reading to high resistance). Only if it stays on for more than, about, thirty starts should you worry. Try clearing the code and see if it comes back on. It was also stated that the ECU dies down the power to prevent damage. I felt it too. This only happened, on and off, three separate times a little over a years time. Staying on for a couple days, then off for months. Then on for a couple weeks, then off for months. Then on for a couple months, now off for a months and counting. 130000K miles now. These are my first toughts.