S6 cold start idle stumble

[AUDIJIM@aol.com]

I replaced the O2 sensor with a Bosch O2 sensor with the correct length and 
connectors. No soldering or crimping was done to get the new O2 sensor 
installed. I also replaced the two pin, white Engine Coolant Temp sensor (ECT) at the 
back of the cylinder head. 

After I replaced the O2 sensor last week, I started the car immediately and 
it worked great. After a few days (over the weekend) I find out it's doing ti 
again, only not as severe as before, and now only after 30 seconds or so.

This morning I removed the fuse for the ECU, removed the ECU, and 
disconnected the battery (I know, over kill) and let it sit while I ate lunch. I also 
added a can of fuel injection cleaner into the fuel tank and took the car for a 
drive. I'm now waiting for it to cool down again and I will see what happens.

By the way, no faults of any kind are present via VAG-COM. Everything appears 
to be operating normal.

ECU output test (done both with the blink code harness and through VAG-COM) 
indicated that all functions of the test(s) were operating correctly.


Jim