02_chevy wrote:TBYODA wrote: What plugs did you use? If anything other than AC Delco Iridium 41-103 I'd replacing them. It is well documented many places on OFTB and GMTNATION that our SUV only run well with 41-103. My 2 c.
ahhh gotcha, They were ac delco but idk what kind ill have to check
did you ever check your plugs to make sure they were the AC Delco Iridium 41-103?
Did you save your old ones?
reading back through your notes, it started after changing your plugs and z71s.
Since it isn't rotational, I would investigate the plugs again.
If you have the old ones(I sometimes keep junk like this as spares), I might put them back in to see if anything changes.