Originally Posted by anscv
What would I look for on the spark plugs? I'm what you might call a back yard mechanic would some basic knowledge. It's been very frustrating working with the dealer, but in general I find this to be true of many dealers. That's why I try to do my own work when I can. I only take it to a dealer when it's under warranty or it's over my head.
Looking at the plugs can tell you a lot about the way the engine (or a particular cylinder) is running. Here are a few links that give some examples:
Link #1,
Link #2,
Link #3