I have a totally stock 2004 F350 Crew Cab, Long Box.
At about 96,000 miles it was difficult to start when hot. The HPOP failed and it was replaced under warranty. The guy told me that I was lucky as the repair would have run over $3500. I told him I would have had to sell the truck to pay the bill!
About 8 Mos. later it started doing the same thing - but it was out of warranty...I didn't want to take it to the dealer if it didn't have to do with the previous repair as then they would have me by the nads. I ended up tearing it down myself and replaced every o-ring...I would have found the issue sooner but the guy I had helping me did not follow my request to find and replace EVERY o-ring. He didnt check the ones the dealer put in at the HPOP area. Turns out it was one of those. The dealer screwed up and pinched the o-ring under the HPOP - half of it was flat as paper. Anyway, after I fixed that and cleaned the turbo everything was fine. Until now.
I know the part your speaking of regarding the stc fitting. I noticed it was a crazy design when I was in there. is it normal for them to fail so fast?
I'm gonna try to pull some codes if I can borrow a reader but I really need something more. Before I go blindly into the HPOP area I want to investegate the the other options.
For what its worth, I pulled the EGR valve and man was it dirty! I mean some surfaces had 1/8" layer of soot. I cleaned it but what else should I do while its out? Is there a way to clean inside the Intake manifold without hurting anything?