Pre detonation knock.

[OHSIXX]

Good point about the plugs.....I heard these trucks are picky about plugs and should stick with Delco ones only.......

 

[CHOO CHOO]

Yeah he said stock or the Bosch irridiums like Joe has. Maybe its a cheap fix and can just change plugs. And at least you will have new plugs!

 

[08grey]

Thanks for the advice. I just noticed I have lazer iridium plugs. This may be the cause. I am going to check and see if I kept the oem ones and put those back in.

I have heard before to stay away from the e3 plugs by the way. The oem number for my 6.2 is this guy. Might be the same for you.
http://www.rockauto.com/catalog/moreinfo.php?pk=1710962&cc=1441073&jnid=438&jpid=20

 

[CHOO CHOO]

Yeah, I'll check those out too. Thanks Joe!