My friend has an 02 6 speed 100 horse injectors super chip and edge easy. The truck just started to get poor fuel mileage and no power when pulling hills. No smoke and falls on its face. Itdoesnt do this all the time. I checked fuel presure. Its a constant 18 when started then will surge down to 16 and i checked the return into the tank and it surges fuel there also in to the filler neck and it has never done this before. On load the truck has constant 18 then will surge when u get off throttle. Is the fass goin out and causing poor mileage and loss of power? Im confused on the surging at iddle and the return line surging fuel back into tank. Any sugestions?