Yeah...I hate road salt...

So I'm attempting to change my front o2 sensor.  The thing seems to be rust-welded to the exhaust manifold.  It's on there good and tight and I'm not seeming to budge it.  I'd bet it's still the OEM one after 152,000 miles and 10 years.

I've been hitting it with PB'laster several times a week for a while now and it doesn't seem to have helped.  I've got a 7/8" wrench that's pretty tight on it.  I just don't want to reef on it and mangle it and end up with a mangled o2 sensor stuck in my manifold.
Any suggestions?

Anyone used any of those o2 sensor sockets?

I've used an O2 sensor socket. They work pretty well. You will probably want to heat the manifold around the sensor with a torch, not the sensor itself, but the manifold around it. Heat it up pretty good and use a sensor socket and it should come out.

Thanks, I'm going to go look around for one tomorrow.  Should I look for a 7/8" or am I actually looking for a metric equivalent?

Actually, at the auto parts store they are just marked "O2 Sensor Socket" and they are really heavy duty and have a cutout along one side for the wire/s to pass out of the way. Should only be around $10 or so(USD)

Use a torch to heat up as previously suggested.  I assume you are removing to replace with a new one, if thats the case, just cut the wire off and use a deep 6pt 7/8 socket.

Victory is mine!  The o2 sensor socket ended up being worthless for this...but I'm not sure whether to blame it on the socket or the fact that I beleive this was the original sensor still...after 10 Michigan road salt winters and over 150,000 miles.   The sensor socket was actually expanding and sliding around the sides of the o2 sensor's nut.
I ended up having to break out the sawzall, cut the thing in two, and then use a regular 7/8" impact socket on it.  With a 3' long cheater bar on my ratchet it came out aft a lot of very short turns...

...4" of honest handle turning, click, 4", click, 4", click, 4", click, 4", click, etc...

Runs a bit better and I'll run the codes tomorrow to see if the front O2 sensor code went away.

To celibrate I went wheeling for 20 minutes or so and checked out an area near my house that I just found...   God, I love these things.