PSD buddies, I need HELP.....04 EX 6.0 diesel with 215k miles, has been great soooo far. Started "missing" at high speed when going up hill so I checked the fuel filters and found they had NOT been changed! The dealer has not been changing fuel filter as they said!! Especialy the one under the drivers side. Tried fuel treatment but still missing also start is rough now. If I accelerate the miss goes away but then returns when acceleration is back to normal. Is it a fuel delivery issue or an injector issue? Looking for new dealer or trustworthy shop to discuss options with. Any suggestions, you guys have been right on in the past!!