Are you going to pull the intake manifold to do it? If so, shoot some photos of the backsides of the intake valves and let us all see the accumulation of crud ( or lack there of). Thanks!!.... hope to change them out in a week or two.
I switched out the original plugs (100K) with the ruthium type on my 2016 Traverse. That helped a little bit. Recently I switched out the coil packs with a high performance type (Dragon Fire). I immediately picked up 1 to MPG in the city and 2 to 4 MPG on the highway. You might consider such a change.Hey guys I know this has probably been beaten to death , what’s everyone’s luck running ngk iridium plugs ? Any luck or did they start misfiring after a few thousand km? Thanks