car stalls after 20 mintues of driving. on 1999 Mercury Tracer

Car stalls after driving about 20 minutes or so.
Took it to the garage. (All codes came back clean).

Bucks when trying to get into second gear via Overdrive.
Bucks when trying to go past 45 MPH. Then stalls. Wait a little bit and then will start. Temp gauge says normal not over heating.

Asked by for the 1999 Mercury Tracer
check coil pack