OK... I had a reputable shop do an A4 to T56 swap on my 98 Z... everything works fine... except the gears whine (problem soon to be solved)... I had a reputable programmer do the work on the computer... Now the car runs much rougher at idle but even more so when you are sitting still and rev to about 2,000 RPM... it's pretty rough. I had a high performance tune put in. I'm running stock manifolds.

What do I do... change the plugs, check the balance on the flywheel, or is it the exhaust that is causing my problem... the car was never this rough before the swap... any advice would be appreciated.