How to change the spark plugs
AC Delco Iridium spark plugs.
ac delco spark plugs are type that originally came with 2003 GMC envoy
they could be bad spark plugs as in not a very good brand. or maybe you didn't put the wires back on the right spark plug.
6
The gap on spark plugs is .042.
the transmition ,is probably not adjusted to the spark plugs,or their not the right spark plugs
Can you tell me how to remove the box covering the spark plugs in a 2002 gmc envoy slt 4.2
Depends on the type of spark plugs. Factory plugs around 70 - 100k depending on the condition of the plugs. I would replace the spark plugs out with some AC Delco iridium plugs they will last you 100k+.
NGK platinum plugs
Maybe when they put the spark plugs in they were not gapped right or they maybe the wrong spark plugs.
Obviously- the spark plugs were not the issue :)