99 pasat lacking power/ hard shifting

somebody please help car ran fine one night the ac would not shut off even when it was in the off position ? the car ran fine! in the morning i started the car and it would not idle code said p1545. so I changed out the throttle body now car idels perfect but when rpms hit 1500 it revs up and dow the car will run but when it shifts it shifts hard and acts like the transmission is slipping but never had problems before please help if you can thanks:banghead: