I have heard that the AC Delco plugs tend to lose their platinum puck into the motor. I have the AC Delco plats in my car and it seems to run a little rough at idle. Could it be that one or more of my pucks fell off??? I dont know if that would make a weaker spark thus making the car idle a little bit rough?? My car also had week O2's for a while and was running very rich and may have fouled some plugs out.

 

I've heard this happens also. Not sure what the outcome would be though. I guess it's possible a little hotter spark could cause a miss against all the other plugs. I'm interested in some info too.

 

Delco makes decent plugs, but on their plats the pucks tend to come off. When I replaced my oem plats with 17k miles on them half the pucks were gone. I don't know if they have improved the plugs since then. It is difficult to say how much this would affect driveability or the idle, but the gap is widened.

 

When I checked mine after 3000,the pucks where gone on most of the plugs.Sounds like maybe you have other issues,maybe wires,or plugs and wires.Try the coil wire first.Could also be a vacuum leak(intake manifold).Hope this helps.(could be something as simple as a gas filter also.)My02

 

I read this before also,if you spray ever so gently on those little wires(or wire) in the mass air sensor with cat approved carb cleaner,that this might help as well.Do the cheap stuff first.