03, 6speed, used to deliver RV's, I put 575,000 on the first set of injectors. I had gotten fuel into my oil so I had them all changed plus the CP3 pump at 575,000 Never did find out for sure where the leak was, figured it's better to just change everything so I'm not in a shop again soon. 35k later, last week I get a knock at idle, espesaly under load at idle, like when you let the cluth out from dead stop. Also extra vibration, half the power at idle. I'm agonizing about this, what do I do? I read the story in Turbo Diesel Register which I had just gotten about injector woes by John Janko page 38 issue56. I decided as a last resort I would try Lucus upper engine lubricant. It said you could fill up your fuel filter with it and called it a tuneup. First I put 1/2 gallon Lucus into 30 gallons of fuel, then drove 100miles, no difference, then I drained the fuel cannister filled it 1/2 lucus, 1/2 fuel, drove 20miles then I thought I could tell a slight difference. Then drove 200miles and guess what? The knock was gone. I drove the rest of the way home and I can say the engine pures like a kitten. And seems to have power like new. WOW what a life saver, Really a MONEY saver. Hope this helps someone else.