But rubbing up against hot exhaust
>isn't fun.
For sure. Go to Harbot freight and they have welders gloves on sale and get some. You want it good and hot if it is stuck because it will expanded the hole it is threaded into. If it still does not break loose, get it hot again and touch some dry ice too O2 sensor and that will shrink it and after doing that for several seconds, get a wrench on it as soon as you can and you could have wrench/socket chilled with dry ice too ahead of time. Do this properly and the physics involved will break it loose.
----------------- TheSnoMan.com