 on an o2 i'm not going to put any nics on them but you know i want to take them out i'd take the plugs out 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