 and look at them and it used to be that if the plugs came out you just change them but at let's say 10 bucks or so 10 12 bucks a plug there's really no reason to change it if the plug is not worn and you'll see the wear on it if that electrode on there's got a groove worn into it it's time to change it or if you've got a lot of heavy buildup on them and they're fouling because of very short trips