Originally posted by DanB:
How can you guys make the determination that the plugs are bad? (other than they look worn/eroded).
At 25k miles on my SVT now, it misfires at idle. Performance is down just slightly. I haven't pulled a plug, but I planned to change them in the Spring. If you don't notice a performance or fuel economy issue, then don't bother checking the plugs. Most issues with new plugs is the gap. Since +4's come pre gapped, no one bothers to check them (and they are hard to adjust anyway). No one can talk away your experience so use what works for you.
