2001 Tranny shifting issues

[kman522]

I thought I posted this on this site before but cant find it?? I might be losing it. I pulled my 28' 5th wheel to the U.P. for a week of camping. Everything was seemingly fine until someone in front of me, about 5 miles before the campgrounds, stopped to turn left on the 2 lane highway. When I took off after they turned, my truck was shifting funny. It didnt want to go from 3rd gear to 4th. I had to feather the throttle to get it to shift. I pulled my buddy's boat around all weekend without any issues. Came home yesterday from a 3 hour drive hauling our 5th wheel and going down the highway, it pulls fine without any issues. As soon as I turned off the highway to get to my house, once again the same shifting issue. I did notice that where my exhaust goes around the rear axle, a hole in the top of the exhaust. Was planning on replacing my exhaust anyways, but when I got to the campgrounds, I noticed my exhaust pipe broke off from the rear of the muffler. Would that heat up the under carriage of my truck, or mess with the back pressure enough to cause my truck to do this? I had my tranny fluid and filter changed at the dealership about 8,000 miles ago. My truck is a 2001 Dodge 2500 4x4 Quad cab short box Cummins with 83,000 miles on it now. The fluid does not smell burnt nor did I ever smell any sort of hot tranmission smell at the campgrounds or at my house when I got home. I have read online something as simple as my battery connections not grounding the tranny. I dont think it is a mechanical issue, I am guessing a sensor or grounding issue. Forgot to say, no dummy lights came on my dash at anytime i was having shifting issues. Does the 2001 allow the use of code reading for the tranny? My SuperChip has a dianogistic tool on it and I scanned my truck and it came up with an error code of P0216 which is a injector pump. :banghead::banghead: :cry: Would a bad injector pump make my original problems of shifting. I have put my foot down on the throttle when this happens and no power at all unless I feather it to shift, then it will slowly increase in speed. Do I need to replace the lifter pump if I am replacing the injector pump?:cry: HELP!!!! Anyone have an idea of what it could be???