Hava a clogged cat. converter which caused loss of power, backfiring etc. In attempting to replace the converter with a new one, I cannot break loose the O2 sensor. Will penetrating oil applied to the threaded area on the exterior of the old converter/O2 sensor damage the sensor in any way?

 

no, you can use some heat as well.

 

Yeah mine were impossible to remove, even after soaking a bunch. I ended up paying a small local gas station to lift it and loosen the sensor for me. Much easier when you can get your whole body weight behind it. It cost $40, but for as frustrated as I was getting I probably would have caused more than $40 damage if I had continued....

 

Someone on here told me a trick to removing o2 sensors. So I'm not taking credit for this in any way but he told me to hit the sensor with heat and then use an air can ( like the ones used for cleaning keyboards and stuff). Turn the air can upside down so that it freezes it immediately after heating it up. When I tried it the sensor broke free like it wasn't even tightened at all. It works like a charm.

 

If I don't need to reinstall the censor. I cut the wires and stick an impact on it. But since I think you need it. I would say get one of those sockets that have a slot for the wire to pass through. Those are handy.