Hello there. I have had my 07 TRD OR for a few years now and noticed a problem shifting about 9 months ago and it is getting worse. I find that when shifting from 4th to 5th (auto trans) the truck seems to hang out in 4th gear until around 2500+ RPM before reluctantly dropping into 5th. I found that if I knock the shifter to the left and then back into D it will immediately change gears. Problem happens mostly on slight inclines, like merging onto the highway, and getting into highway speeds. Seems to lessen after driving for a period of time.
This problem is probably contributing to my bad gas mileage (275 mi/tank) and is potentially effected by some codes I've thrown for a little while as well. My check engine light came on not too long ago and when I ran the codes I got 1-2 bus 02 sensor problems. Since then I have cleaned the MAF and throttle body, changed the plugs and the battery, but still get the check engine light.
Do you think that the 02 sensors are bad and are contributing to my shifting problems (trying to warm up the engine by staying in OD)? Or are the two problems unrelated. Either way, I'd love to figure this out soon. Thanks for reading through this.
/disclaimer: I have not been as proactive about this as I should have been, and the problem is likely getting worse due to my negligence.