I went ahead and got the APR stage 1 ecu for my 1.8T quattro (automatic trans) and now im having issues with the trans shifting back and forth under moderate acceration at about 75mph, also hit the gas at 45mph and I hear a big thud when downshifting. When I use manual mode it works fine so I dont think there is a problem with the trans. When crusing or just drive lightly I have no problems. PLUS my gear selector display is not lit up so I dont think I have any tranny codes. Cant get ahold of anyone at APR to help so im asking you fine folks.

 

You're gonna have to get a hold of some one at APR most likely.
Sounds like they didn't get every thing set up for the computer and your transmission the right way.