99' GTP won't go!!:(

My gears won't change right. I'm having to change gears manually the RPM's run real high just to get the car moving! On the interstate the RPM's run real high around 3000 to 4000, I also have my supercharger unhooked, and noticed a vac line that is dry-rotted.. This is a reman trans. with about 20,000 miles on it.. and I've flushed and serviced it last week, but it didn't help...any ideas:shakehead

What vacuum line is dry rotted? The PCM uses various sensor signals to trigger shift points. All of which could be affected by a "rotted vacuum line".

Friend of mine has a 2000 GTP and his was acting up also, wouldn't shift right. He was ready to have the trans rebuild. I went over there and watched the data stream with my powertuner and found out eh MAP sensor vacuum line was split. Replacing the 90 degree elbow fixed his issue.