I just had my tranny rebuilt in my 2006 Silverado 1500 Z71 last week and it is having some issues. Every now and then it will shift really hard and throw P0894 code. Most of the time it will shift alright. Trans also hit 180 degrees today for the first time not sure if that is normal. I think it may be a software issue but not entirely sure. Trans has a transgo hd2 shift kit in it and a Diablo factory tune with the wheel size and axle gear ratio parameters changed. Can anyone give me a clue as to what's going on ?