i have an 07 f350 with the 6.0. i beileve i have a hpo leak but im not sure... i drove to work parked it for about an hour tried to start it back up to leave again and it wouldnt start. I let it sit for about 4 hours and tried to start it back up and it started just fine. so i drove it to the ford dealership bc i still have a warranty on it and they still havent got around to looking at it but just the way it acted led me to beileve that maybe the dummy plugs, sct fitting, or the stand pipes have gone bad. if im not mistaking they all have o rings on them that are known for going bad am i correct???