How do I unscrew an impossibly tight front oxygen sensor?

[ski.dive]

1. I used the oxygen sensor socket on the front oxygen sensor by the rear spark pugs , but the thing WILL NOT budge. It's REALLY STUCK on.

   Any tips on how to remove these?

Edited April 1, 2018 by ski.dive (see edit history)

[DAVES89]

Start and run the engine until it is throughly warmed up. Turn off engine and try again. 

[Dashmaster]

 Also If you have a long enough socket extension you could try a breaker bar on it.  If none of the above helps try a freeze spray or you could soak it with PB blaster, let it soak good  and try it again. 

[retiredmechanic74]

If your replacing the sensor bust off the top of the sensor and use a 6 point impact socket 7/8's in size. 

[Bleach]

I had a O2 sensor on a SBC 350 that was stuck that after much effort came out with some of the manifold's threads. Luckily there were enough threads left to install the new one.

[Digger914]

If the sensor has become one with the threads as they sometimes do, even the blue tipped wrench won't get them out without taking some thread. But if you have an oxy torch heat all the way around the bung until it glows red, before you go after it like it's that thing or you. 

[D-a-n-i-e-l]

Look at the opening of the socket. If it tapers then grind it flat to get you a better grip. I have done it a couple times. If that doesn't work weld it to the 02 sensor. Had to do that when using seafoam pretty much welded my 02 in.

[SteveT]

Beeswax.  I was taught this trick many years ago . Beeswax is one of the most effective penetrants you can use.  Heat the area where the sensor threads in ,  hold the wax against the sensor and watch it wick in.  It does not require a blue tipped wrench , a propane or mapp gas torch is sufficient. For 40 years I always had a chunk of beeswax in my toolbox and constantly amazed the younger techs working for me with how amazingly well this works in most cases.

[Jerry Moriah]

Acetone and transmission fluid,  the machinists penetrate works miracles on old severely corroded exhaust studs. Also hot, then ice cold  and penetrant while still a little hot, repeat,  with patience, till it breaks free.  Apply pressure immediately after cooling sensor body.

[Ronnie]

The best penetrating oil I've used is AeroKroil. It's a little expensive but it can work miracles if given a little time to soak in.