I have a 2004 Sunfire. Whats going on is after an hour of driving it, it shifts real hard going into 1st to 2nd. I have no CEL. I took it to Auto Zone and was unable to pull any codes. I took it to the tranny shop and they dove it around on the computer and stated it might be a sensor.
It sounds like its shifting to early. I can turn the car off then back on and its fine for about 30 mins.
anyone know what it could be?
its a automatic tranny with 101,000 miles.