Trying to change 02 sensor. Cannot get it off. Any suggestions. I am useing an o2 sensor wrench, but cannot budge it. Should I try it with the headers hot or cold? Penetrant oil? Cutting torch. TNT? Thanks for any advise.

I ran into the same problem. Tried as hard as I could, wouldn't budge.

I eventually got it off by letting it soak in penitrating oil overnight, then using the right size hex wrench.

I had to cut the wires before hand, so if you try it this way be prepared to be unable to drive your car if you still can't get it off.

After that it goes pretty smoothly.

I apreciate your good advise. I quit trying to use the 02 wrench, just cut the wire really close and used a deep socket. After 2 hours of soaking it with penetrating oil it came right off. Thanks again.