Today a lesson was learned.
I had driven the truck to New Mexico and on a stop headed there, I noticed there was some soot on the fender by the tailpipe. The truck sometimes felt like it was missing under acceleration, but I never got a CEL.
I bought the truck used from a dealer with 61K on the clock. I specifically asked them if the 60K service had been performed and they said that it had. I had changed the fluids in the diffs, TC and tranny and the diff and they didn't look too bad. Well, I got some time to check the plugs and found that it still had the
OEM plugs, Denso on the passenger side and NGK on the driver's side. The stock gap is .040 and the electrodes were so worn on these that they measured at .085. No wonder it was missing!
The plugs that came out:
Comparing old vs new:
I ended up buying NGK Iridiums for $7.xx each.
Put them in, now it purrs like a kitten. The only things I removed to change them was the airbox on the passenger side and only had to unbolt the bar that holds the fuel line block to the engine. So, the lesson of the day is, trust but verify. :sombrero: