O2 Sensor stripped threads
 

Pulled my O2 sensor today, after a lot of work. The thing was even bent slightly. Not sure if it was ever changed...

Threads are completely stripped

http://forums.pelicanparts.com/uploa...1377207044.jpg
Here's a compare with the new

But the threads in the pipe looks decent, except what looks like the missing O2 threads mashed in the last pipe threads

http://forums.pelicanparts.com/uploa...1377207116.jpg

So, what now? get a tap and try and clean the threads? Do I have to remove the whole cat to get this done right? Any other way of cleaning up these threads?

The new O2 sensor won't go in, not at all.

My first attempt would be with a night-long soak of PbBlaster and then a propane or MAPP torch to free things up, and try to engage the leftover thread material with a dental pick to break it loose. It looks very salvageable.

After soaking might try digging it out with hook scribe, it isn't as brittle as a dental pick and less likely to break.

Sounds like trying to pick it out before trying a tap is the way to go then... I'll try and do that tomorrow

Thanks guys. If anyone has input, please feel free to blast it at me.

How did that even happen? yikes

Who knows. Not sure if it has ever been changed. It was rusted pretty good. I used an O2 tool socket to loosen it, but when it was turning it was crooked. on the last few non existent threads it just spun, so ended up bending it out.

Untested ideas - and probably not good ideas:

Epoxy the old sensor back to the threads then soak with your favorite penet. oil, then break it out. Assuming the threads are sitting there. Obviously this is nuts.

There is also the opposite way to go with temperature - FLAPS have a freezing spray - why not go both high and low - but don't fracture the exhaust pipe.

Try Garage Journal

an air can upside down also freezes.

i'll try heat and picking tomorrow. and maybe freezing

Auto parts stores sell a O2 sensor tap. I have used it in the past and it worked well. I got mine from the local Parts Plus store...It cost about $12.

Sure, just chase the threads with a tap and you should be fine. That bung welded onto the pipe is much more substantial than the threads on the O2 sensor and will hold up well.

Can't help but think this would be much easier to work on if you were not on your back under the car. The cat is not that difficult to remove with a good dose of your favorite penetrant on the nuts/bolts.