let me as you guys this question. my 99 gtp has done the same thing to me 2 times now. i was going to alabama last week end and went up a mountain twards fortpayne and the car downshifted to 3rd while driving up the mountain. once i got over the mountain the car never shifted back to 4th. i tried manually down shifting to 3rd and back to 4th and it never did anything. felt no shift or change in rpm. i figured 4th was gone. said oh well and drove for another 15 miles and got on the interstate running 80 and still in 3rd gear. After about 5 miles it finally went in 4th gear and has been doing fine sence. scanned car and there are no codes. Whats The possible cause.
