Thanks for the reply, it's stock except for the MSRP dual cat back 4" exhaust and a Diablo Sport Predator tuner for tire size adjustments. Will try the additive as you had mentioned, just want to make sure that I'm not causing damage to the motor. I do haul a 10,000 pound camper from time to time.
I have a 04.5 lly with 103,000.00 miles on it. I noticed lately that when I start out cold for a bit, it has a pinging or knock to it much like the pinging in a gas engine with low octane gas. Has anyone else had this problem and if so what was the fix for it. Any help would be much...