Not sure if this should go under trans section or not:

So I just got the car last week. It's a 2004 GTP Comp-G with 94k. It's bone stock except for a CAI. After driving for a couple hundred miles to make sure everything was solid I decided today would be a good day to open it up. While accelerating today at WOT it would not go passed ~85mph while in "D". It seems to just hang in gear like it hit a limiter and stays at high RPMs. If I switch it to tapshift mode I can shift into 4th and continue to go. The car shifts into every gear every other time just fine. Trans temp stays around 190-201(outside temp 60). No codes no stumbling. I'm a little stumped/concerned as to what could be going on.