I was on the last part of a road trip when I hit the gas to pass someone. Everything was fine until it tried to drop into passing gear. The engine hit about 4k RPMs and then it started to stutter. I took my foot off the gas and it continued to stutter for about 2 more seconds. The problem is reproducible. I can rev over 4k while in neutral and I can normally accelerate up to 80. I've recently changed plugs, wires, fuel filter, air filter, PCV and did an oil change. I've checked the trans fluid on the dipstick and it has enough fluid. Any suggestions before I drop the pan and have a look?

 

On the engine end of things, search this forum for MAF sensor and IAC valve cleaning instructions. If these are dirty/clogged, the computer makes bad decisions, including shifting.

On the transmission, smell the fluid and check its color. If it is brown or smells burnt you are overdue for some wrench time. A key factor is if the transmission has been flushed and the filter changed every 30k. If so, do another flush/filter. If not, only change the filter and start saving for a rebuild.

 

Thanks for the advice.