I recently installed a 52 mm throttle body and hypertech power programmer on my 94 LT1 A4. I think these parts might be causing the following problem:

Whenever I accelerate from 0-15 mph very lightly, the throttle will get stuck at about 1000 rpm. I can take my foot off the accelerator and car will just keep going at 15 mph unless I apply the brake.

Also, when I come to a dead stop, the car will idle at 1000 rpm instead of the 500-700 it used to. If I put it into neutral, it jumps up to about 1500 rpm. If I go into Reverse and back to Drive it usually goes back down to the regular 500-700. If I rev it while it is at the 1000, it will also come back down to 500 as well.

Can someone please give me an idea of what could be my problem?