anticsAK

Ok, so i just bought a 97 A8 with the 4.2 with a bad hesitation under a load, but smooths out after 3000 RPM's. If you drive it in 2nd it stays above 3 grand, you can drive 55mph and it only has a slight shake (how bad is that for the car anyway? longevity? And on the transmission?). He said he parked it once the problem started changed a coil pack that the cylinder called for a misfire, and that didn't fix it and so it sat for a year. So through my forum searching i have narrow it down to the ice's. I purchased one of amazon for 29.99 and swapped the BAD one out. stated car and it ran the same. so i thought i may have swapped the wrong one so i switched it withe new one and put the old one back that i had originally swapped out. and now the car won't start period!!! i thought maybe i needed to reset the MIL light for it to recognize the new module. and maybe when i swapped sides it also had a misfire on that side so it thinks theres one on each side? and it cant run on 6 Cylinders I'm guessing. so i put it back to the way it was without the new module and it still won't start!! But alkl the forums say they just changed it and it took. The only other thing i can think of is its signal being sent to the icm is to high of voltage and it frying that connection, so when i swapped the icm it could have fried the one to. is that possible please help!!!! i want to see what this car is about that i bought.