2000 6.0 Tons of KR

[cdiggs21]

Have a completely stock 2000 2500 6.0 truck that has been feeling like its really down on power so i logged it and am seeing tons of KR while under normal acceleration. Plugs/wires and coils are all brand new and the truck is on 91 octane. I attached a log of it any help would be greatly appreciated thanks! 2000GMC6.0KR.hpl

[5FDP]

Investigate a vacuum leak or exhaust leak. Check the intake gaskets and exhaust manifold bolts.

Based on the fuel trims, you have something going on. Often times the long term fuel trims are fairly positive at +10-16%. Check fuel pressure and make sure it's within spec at idle and under driving conditions.

Check for anything rubbing and the condition of the motor mounts and transmission mount. Extra vibrations can be picked up by the knock sensors.

And you'd be surprised how much knock is built into some calibrations. If there are no known issues wrong with the engine and no pending or current knock sensor codes you can do a few changes to the tune to help reduce/remove some of the knock under heavier acceleration.

[cobaltssoverbooster]

ohm the sensors at the sensor harness. if they go out of range they pull timing. did it to mine. there are tsb's for the valley cover knock sensors so its always worth a quick check when you have kr problems

[55Belair]

It seems that these Gen III 6.0L are very sensitive to KR, there has to be something collectively going on with these.

I noticed that your IAT is north of 125* and does not drop significantly during the run. That could certainly cause the KR and would affect the low power output you describe. I had high IAT on my swapped 6.0L that caused KR. I rerouted the cold air intake that made it a lot better but didn't cure it entirely. I'm still chasing down the final piece of the puzzle.