So far no codes from the tranny (fingers crossed that they dont pop up) but it seems like it slips a lot going from first to second. Also it seems to slip 2-3 and 3-4 after long trips for about a month.

As far as an LS4 goes, thats way too expensive. I would have to worry about wiring harnesses, plumbing, all that stuff. thats too much work for me. One benifit though is that bolt ons are easier to come by. Im going to stick with the SC 3800 idea, less work, im a bit lazy. I also have other places to dump money than an LS4, like a 1974 Dodge Challenger in need of a new metal.

I would guess to say it may be the Pressure Control Solenoid in the tranny. I would check the fluid first but the PCS is pretty common to go out in the tranny in the Monte Carlos.

Old post but I guess someone never looked at my transmission tube thread. Sounds like that trans had classic symptoms of loose tubes. No codes and slipping.

The thread is over a decade old and the OP hasn't even been on in 3 years. Car's probably been handed down to his grand kids or in the junkyard by now, lol.