1999 ram 2500 cummins;at 45 to 52 mph it is going in and out of lockout anyway I think that is what it is called. It's like the 4th gear. I changed the tps because the dealer said that is what they did a couple years ago when it was acting the same way.But any way it is still doing the same thing with the new one,and also the check engine light came on after puting on the new tps. HELP me please

 

The first thing to do is ck your codes than get your pcm flashed,from there it gets more fun.Tons of posibilities..........
Bob