98 lumina oxygen sensor post cat removal

It is so tight might have to take it somewhere to get it removed. I've tried a torch and penetrating oil. I can't get an impact wrench on it. Any tips greatly appreciated. It probably needs to be on a lift and a 3 foot long cheater bar cranking on it. I can't get leverage under the car just up on ramps.

First Guess: Threads are seized. Once you get it out, you'll have to re-tap the threads in the pipe before cranking the new sensor in.

Common as dirt. No amount of penetrating oil is going to help. Heat might--or might not--help.

Things get too bad, there won't be enough left of the bung to re-tap. Then you get to weld a new bung into place.

You can spray penetrant, like PB Blaster to the threads, several times on a cold exhaust.....give it some time, like an hour.....then start car and get to normal operating temp......shut off.....use a flex head breaker bar(with pipe if necessary) on an O2 sensor socket......work it back and forth....

Should come out.....but it may damage the threads......they are the same thread as a spark plug......so you may need a spark plug chaser.....

As Shurkey said, it's possible the threads could be damaged., so that a thread chaser doesn't help.....

Thanks for the tips. I found another idea and that is hit it with a hammer and chisel. I did that then sprayed more rust dissolver. It came right out and the threads looked perfect.