For anyone else looking for an alternative removal of an O2 sensor (only if you're not going to reuse it): Destroy it down to just the nut and use a 6 point socket with a large breaker bar. 1/2" worked the best for me. Then buy a thread chaser and be done with it.

OP sorry you had issues brother. Little things like this suck the life from you sometimes. I just replaced my cat with a Euro pre-silencer. What should have been a couple hour job turned into a week long life struggle involving multiple power tools and various cutting/drilling items. I won, but the cost was high on both sides. 31 year old West German steel bolts became "one" with the exhausts flanges. Not fun.

- Steve

"M18x1.5. Old Fords used this thread for spark plugs, so thread chasers are pretty available. Here's a tool number from Google: Lisle LIS12230 Oxygen Sensor Thread Chaser. I'm guessing you'll find it at your FLAPS, but it might be WAY cheaper online.

The Cap'n"

I love info like that...

This is good advice. I was originally trying to save the sensor because, like someone else asked above, I didn't actually know if my sensor was bad. However, like the threads in the bung, the ones on the sensor are totally trashed so I couldn't reuse it anyway. In the future I'll probably hacksaw off the top of it so I can just stick a regular socket on it.

I'll also probably get a torch, too. :)