Ok so i drive a 4g64 automatic 4 speed with OD and lately every time i use OD the gear pops out when i hit third gear and when i press the peddle it rev's and doesnt go any faster, when i take off OD it goes into third but i cannot go in my fourth gear. Anyone know what is wrong or what happened? Thanks!

Really think there might be something wrong with your tcu cause I know on automatics they have a computer for the trans, and correct me anyone if I'm wrong from when I last remember, a stock 2g auto has only three drive gears. So I think the computer isn't allowing you to shift into fourth because of that, so that's my guess, but elaborating more if you can

Elaborate*