Key to stuck plugs is a hammer and taking it slowly. You dont want them to break off in the head or your talking mega bucks.
You get one started hitting the ratchet with a hammer and you tweek a little to get it loose and then tighten it back up. Tweek a little further and tighten it back up. And do this till it feels like it will continue to come loose without to much trouble.
This way you will be working the threads then going full force and twisting the ends off in the head. Been doing them that way for years (knock on wood) and havent had one break off yet. Infact I did the tune up on my wifes jeep today and had 2 of them stuck and that is the only way to do it. OH and the engine needs to be cold not warm or hot
And also use no or the shortest extention you have. The longer the extention the less of a shock inpact from the hammer will be applied to the stuck plug. And keep that sucker straght and not cocked off to the side where you will bust the porcelen off.
And to pass emmisions find the PCV valve and remove the hose. Stick a good wad of paper in there. This is so you dont take back in the blow by from the engine. Also take out your air cleaner if it is a place that will not check to lessen the restiction of air going into the engine alowing it to breath better. Make sure to bring it there very hot so try to get it there right off the highway or go beat the crap out of the car to remove any cabon build up inside and heat it up really good. And use low octane fuel and near empty tank. The car will lean out so near empty and using less octain will allow the car to burn all the fuel. Higher octan is harder to burn so it may not burn it all up. And up the timming a smidge to the point it just wants to spark knock. Spark knock is the fuel detoning before the spark plug has a chance to light it up. You get it a chance to burn all that fuel setting the timming a little more advaced and you wont have anything come out the pipe at all
