is it possible that a bad O2 sensor will prevent the trans from shifting into overdrive? after replacing my O2 sensor the other day jeep has been running better than ever. now at 70 mph i'm only turning 2100 rpm. before swapping O2's i would be at 2800 rpm at 70 mph.

 

Did u have a CEL......wouldn't think a properly functioning O2 would prevent shifting to OD. Low engine temp can delay shifting to OD.

 

yes i did have a cel for the O2 sensor. no problems with low temp either.

 

Sounds like you are going into overdrive higher gear= lower RPMs

 

Im at 2000rpm going 60 with 30x10.5 on stock 15x7 stock gears. Does that sound right? I feel like its too high? What does everyone else cruise at?

 

Google rpm calculator. itll tell you what your gear ratio is and you can figure where your rpms will be with lower gears/taller tires etc