Here is the deal with my 03 with 196K miles. I have dead pedal situation. It seems my shift points are off too, it revs pretty high, pretty fast. From 2nd to 3rd to 4th gear I can hear the rear tires bark on the road.
I done all the research and it leads me to the APPS. When I use cruise I
don't notice any acceleration problems.
I have done the APPS reset a few times and it doesn't fix anything.
I am almost ready to buy the TIMBO APPS but I really don't know.
I have the write-up from Chip Fisher about how to diagnose VP44 fuel issues and now it sounds like my it's my VP44.
During my troubleshooting on the truck I did the key test to pull the DTC codes. I got the below 4 codes.

P0642 Sensor Reference Voltage 1 Circuit Low
P0483 Cooling Fan Speed
P0514 Battery Temperature Sensor Performance / Rationality
P0107 Manifold Absolute Pressure Sensor Low

I have checked all wiring harnesses and wires, looking for worn wires. Found nothing.
I have checked all fuses. Nothing found.

I have replaced the fuel filter when this started and I have added some fuel additive incase I had any water in the fuel system. I even read online that putting sea foam in the tank takes care of some of these problems.

I am now at a loss of what to do. I have already replaced the lift pump a few years ago. It might be the lift pump again but I am wondering if it might be the VP44 now.

Anyone have any ideas or advice?

 

03's don't have a Vp, they are commmon rail trucks,

 

Thanks for setting me straight. Sorry for the mis-information there. I meant my high-side injector pump. I replaced the low-side lift pump a couple years ago. Could this be a injector pump problem? Or am I looking at sensor or ECM proplem?