I have owned a few cummins trucks now but always had newer ones that I didnt have to work on. I just bought an '02 H.O. 6spd with 200k on it. For the first few days it had what I have read to be described as a "dead pedal", but only at low speeds and mainly before engine gets up to operating temp. Usually I could just pull over, turn the truck off and right back on and it would be fine for a while. I did a bunch of research and narrowed it down to the apps sensor. I purchased a new one and adjusted it to the correct voltage, but still had the same problems. Now today, I was driving it and everything was fine, came up to a red light, and when I went to take off had zero response from the pedal. Truck starts and idles fine (one time after I started it again I was able to rev the engine once then it went back to no response). Checked the APPS voltage again and its working fine. Put a scanner on it and it shows the voltage is fine. If I use the "key trick" I only get code 1693. The scanner picks up P0216 and P0121. I have tried the APPS reset also.

Please, any help/insight to diagnose further will be greatly appreciated.