2nd Fred on getting the codes. It's probably not a "shifting" problem. A code will reduce boost and/or available fuel making the car feel sluggish. It will also cause it to "hang" in gear if the accelerator is held to the floor.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250