Oxygen sensor removal

Hello again,

My downstream oxygen sensor needs replacing. Only trouble is, i cant get the damn thing out !! Why oh why did GM put it on top of the ubend on the converter ? I cant get a socket onto it so im stuck trying with a regular open ended wrench. Ive tried when the exhaust is warm, ive tried spraying WD-40 in the thread, ive tried with all my strength to get the thing out, ive even tried banging the wrench with a hammer, but no luck. Im afraid if i put a pipe on the end of the wrench for the added tourque i might break something on the exhaust. The whole system moves slightly when i force on it.

Does anyone have any tricks to get the thing out ?? What about removing the catalytic converter and working on it then ?? Or when the system is burning hot ?

Thanks again

-Steve

PS i spent all weekend working on my car, can you tell :)

Try a better penetrant like PB blaster or Break away. WD-40 is good for removing water and stopping squeaks, but it's useless for breaking rusted parts loose. If that doesn't work, try starting the car, getting the pipe warm, then spray cold water on the sensor.

go buy a cheap wrench and slit the closed end so you can get the wires through it on the O2 sensor 6pt wrench it holds better

the O2 sensor is on top of the ubend, impossible to get a socket over it, even a special socket, believe me ive tried ;)

:nono: wrench I said

Let the engine get hot this will come out easier.

Let the engine get hot this will come out easier.
Actually letting it cool down, soaking the threads with brake fluid and it will come out with an open end wrench.
If it turns a thread or two, resoak it and turn it back in..wait a couple minutes and unscrew it.

I don't know a hot pipe seems to be much easier to get them out from my experience. Same as you would heat the area to get any frozen bolt out, but you are right about the penetrant, that wouldn't work on a hot pipe anyway, two approaches I guess.

Where can this PB Blaster and/or Break Away be purchased? Also, can this stuff be used to free up my fuel filter nut, having a helluva time trying to free it up. I'm being VERY careful not to strip the nut: 97 GP GT 3800 106,000

can this stuff be used to free up my fuel filter nut
I used PB Blaster on my fuel filter when I changed mines. Walmart sells them under $4 a can.

UPDATE !!!

woohoo ! i got it out :)

I couldnt find any PB buster but i boughta tin of Gunk Liquid Wrench Super Penetrant. That, combined with a hot exhaust, and a very long wrench got it out. The tip of the old one had gone all white and showed signs of wear, so it was definitely up for a change.

THANKS for all the suggestions, i guess a combination of all of them, along with some perserverance will get this job done !

-Steve

I paid the nearly $10 for the removal tool (AZ) and my breaker bar. Worked like a champ. The metal housing on the old sensor cracked in the process but I had already determined the sensor was indeed shot.

I paid the nearly $10 for the removal tool (AZ) and my breaker bar. Worked like a champ. The metal housing on the old sensor cracked in the process but I had already determined the sensor was indeed shot.

Please check the date of the thread or last post before pulling up old threads. This one goes back over 5 years. No issue doing so except possibly getting some criticism from the membership. Best to start a new thread and share your experiences that way.

I had the same problem my downstream o2 except mine was crossthreaded on. Plus instead of having had some kind of anti-seize on prior the being installed, it had something that did the opposite and acted like a jb weld.
I got it off after droping the exast from its hangers and letting the car warm up. But because the first three or so threads on the cat were destroyed, I eventually dropped the whole exast, bought a oxygen sensor chaser(also known as a tap) from autozone and after 4-5 trys was able to tap out the threads. hope this can be to some help to someone.

-Matt