i have a 2003 gmc 1500hd that wont shift into overdrive anyone have similar problems? i need to replace my bank 2 sensor 2 o2 sensor so i have a check engine light on, could that be throwing the truck into limp/home mode so it wont shift into top gear? also this is intermitten as well as my check engine light.

 

If you have any data logging software, check for any misfires. A misfire will cause the TC to not lock up. Also make sure your bank 2 sensor 2 is the only code stored.