So did you resolve the issue? How you described it sounds like I’m having the same issue I accelerate and the rpm’s just keep going almost to red line and doesn’t auto shift from 1st I have to let off the gas and accelerate slow and it’ll get back to normal I replaced the spark plugs along with spark plug wires Oem Acdelco , ACdelco fuel filter , oil change , new air filter ACdelco downstream 02 sensors previously had a code for it changed them out along with the fuses and has zero codes and nothing still my next thing is changing out the trans fluid and filter and see if that does anything.
