Hey friends, new to this site and a buddy told me to log on for help. I have a 2003 cummins 2500 and recently when out in the hills hunting, i experenced an issue with the truck not responding when i accelerated on the throttle and it acted like it wasnt getting fuel. It would die out on me but thankfully it would start and i made it home. took it to the shop and the man told me it was the throttle positioner sensor on the diagnostic test. he replaced it with a new one and no luck and no charge and he told me to take it to the dealership because it seemed to be a computer problem. Ive had many tell me it could be the lifter pump as well. Any ideas?

Thanks!