I have a 02 a4 1.8 turbo with no check engine light at all and only 90,000 miles. Runs and drives excellent. But between 1-2000 rpm it hesitates. It kinda jerks. If you are at full open throttle from a stop you won't get any issues. But just driving around town this problem is around. We did 4 new coils and plugs(dealer parts) the other day and didn't improve it. We saw oil leaking from the valve cover so we replaced that. Smoke tested it and no leaks. Bought a new throttle body from the dealer and had it programmed and the car actually has this hesitation problem ever worse. Any ideas? This car is pulling no codes and Audi of Brookline even scanned it and can't pick up any codes. They said "it might be a torque converter".

 

I have been having this exact same issue with my 2003 A4 1.8t FWD and have been doing a lot of research on it what I have found recommended is to change the transmission fluid and see if that helps which you can do yourself I will also be doing this in a week or two. I also read about the torque converter so if you replace that please share your results. Also it could be the Transmission Control Module I have read so there are a few things to think about hope it helps and good luck.