2000 Monte Carlo LS 3.4l. The trans. work good, shift up & down smoothly. But "ONLY" when I squeeze the gas pedal to the floor, the trans doesn't shift to 2nd.

I remember now, this was about 2 years ago, I took my car to a friend shop that he have the scanner. The scanner reads some solenoids mechanical problem. My friend suggested me to pull out the rear trans cover, and clean-up all the solenoids ends to see if that solve the problem. But I never did, because my job. Like I said, the car still runing, and shifting fine. But I can't race. Thanks for answering!!!

Yeap, I think should be better replace them all at once, they're only around $20each. That way I know for shore I will have long time good performance from the trans. Thank You, for you time.