I have a 2001.5 S4 and when it was stock the car had kinda a jerky power band. It did not cut out but just seemed kinda fluttery if you payed attn to it while driving. I have only had it for a month. Couple days ago I did the 91 oct APR chip and the power band is more noticeable as not being very smooth. Is this normal for turbo cars? It almost feels like your foot is shaking ever so slightly as your accelerating causing power to chater as well.

 

could be a boost leak, check your throttle body boot, diverters and vacuum lines surounding. usually the tbb tears by the clamps. if you hear a whoosh type sound coming from under the hood thats usually what it is. depending on the mileage on the boot, when you chip the car and put it into 91oct mode it will tear it right apart :-(

 

Its should be smooth

 

Well, pulled off my throttle body boot today and it was perfect. What about my div valves.. Will that cause a problem? They are still stock. Will they leak boost since chip upgrade? Its a very slight chatter in powerband.