Yesterday truck started to rendomly "rattle" and seem to miss, for about a second or two then go back to normal. The rattle sounds almost like a cold 12V. Then it seemed to hesitate when leaveing a stop then rattle and rpm would jump to normal and away ya go. This morning went to pick up daughter and going up a hill now it is down on power, you rug it and its like driving a 4 cyl sprit. Havent check for codes yet.

 

Fuel pressure test ? & codes ?
Maybe bad fuel or filter change , drain some fuel from filter into glass jar to see how it looks .

 

just checked for codes and the only ones are P 0462 and 0463 fuel gauge is not reading proper and changed sending unit with used one because you cant get just sending unit once dealer does the lift pump relocate, you have to buy the whole "kit" for 500 bones. The different sending unit is doing samething, full tank reads empty then about half tank it goes to full. The fuel pressure from FASS system to injector pump stays at 12 psi +/- half a pound.

 

update: changed fuel filter on FASS system and still down on alot of power. Disconnected Edge box and no power gain. Reinstalled Edge box tryed agian on stock it runs like stock for power, lvl 5 power increase but total power still down. Truck runs smooth at highway speed but seem louder from the engine. Fuel pressure is still steady at 12 psi and boost at stock hits 25 psi rugged and 29 on lvl 5.