That happened to me once. Look at the plug, it will look like little more then a scratch.

Well, I misted the coils and wires around the plug areas and fired it up. Didn't notice any arcing. So I misted some more, and it started running bad with the check engine light blinking.

Didn't get a chance to pull and look at plugs, but it seems pretty obvious that the problem is in the neighborhood of the plugs, wires, or ICM. I'd like to think that it isn't the plugs because they only have 30k miles on them, and they are AC Delco.

If I go and grease everything, is it kosher to grease the plate where the coils connect?

Should I just replace the plate and coils?

How old are your coils? If they have never been checked then perhaps they should be replaced. Have you tested the coils? Clean everything up and put dielectric grease on it to keep it clean.

The coils are probably stock, and one of them looks to have been swapped with another used one, or something: I have two coils labeled 2/5

You can test them. No harm in doing that.

Okay... did a forum search on testing the coils, and I might be blind, but I can't find anything. Mind telling me how that'* done? thanks!

on the home page half way down there'* gm general tech info/ troubleshooting and test procedures. dans got a bunch of good stuff there.

https://www.gmforum.com/trouble-shooting-test-procedures-141/testing-coils-spark-plug-wires-278818/

if you got two coils that say 2/5 one is from the junk yard because new ones dont have numbers,

Thanks!