I'd do the lift pump first since the truck probably hasn't had it ever replaced. I was on rockauto and it looks just like the 6.5 lift pumps in my '95 but with a different fitting/harness connection. It's as easy as replacing a canister fuel filter. It's hanging on the frame rail midway between the bed and the cab. A properly functioning lift pump takes a ton of stress off the rest of the injection system. Check out Napa, first and see if they still have the lifetime warranty on their lift pumps.

So that’s just it and part of the injector issue is GM DID NOT install a lift pump in this Dmax version. They just have a CP3 fuel pump which is sucking fuel a long ways. This compounds the issues with the injectors .

The aftermarket offers external options, these come with extra filter and water separators designed to assist and clean fuel. There is also an internal fuel tank pump as in option , but this offers no additional external filtration. Depending on the “expert” you talk to gives pros and cons to each.
Everyone does agree that is a must have addition so I’m down the proverbial rabbit hole. If anyone has real world experience please do tell.
Truck runs great, I enjoy driving it.

Very interesting! You're telling me that the 6.5 engineers actually had ONE thing they did right? :wink: