I've got a 2000 a4 and i recently put 3.42 gears in it and a TSP rumbler catback. Ever since i put the catback on it doesn't seem to have as much power as before and the tranny doesn't kick down like its supposed to when i mash the pedal. It works maybe 50% of the time. I tuned the car with a HPP3 for the gears and i chose to firm up the shift points also. I didn't adjust the shift points yet though. Would this have anything to do with the problem? Any help will be appreciated. Thanks