Im having a miserable time trying to remove the passenger side o2 sensor on my 1994 Z28. I've already removed the Y pipe and the starter. Now I can get a wrench on the o2 but it absolutely will not budge one single inch. I've let it soak in PB Blaster for 2 days, I've heated up the exhaust pipe with a propane torch for 15 minutes or so, I broke most of the sensor off to fit a ratchet on it with a 7/8 impact socket and then put a cheater bar on that trying to get more leverage on it. All with no effect. And now it's beginning to get rounded off since the o2 is so close to the Y pipe flange making it hard to seat a socket or wrench completely around the sensor. Do you guys have any advice on what I should do? I'm laying beneath the car on ramps so I can't get much more leverage on it than I've already tried time and time again

 

Are you using a regular 6 point socket or O2 socket? Once you get the O2 out, the threads may be damaged and you may have to get a thread chaser. A spark plug hole chaser is the same diameter and thread pitch.

 

Cut the body of the o2 sensor off and hammer the tightest fitting 6 point socket on there you can then impact it off

 

If you can't get an impact on it you need to either put a 6 point box end wrench on it or 6 point socket on it then wail on the wrench/ratchet with the heaviest ball peen hammer you have. The goal is to "shock" it loose.

 

Is the sensor on a header collector or some other thing, and is that thing still attached to the car? If so, do what you can to get the part out of the car where you can work on it. Worst case, you'll spin the 02 in half and will have to drill it out, then drill / tap / insert new threads with a Heli-Coil or TimeSert. (Ask me how I know...). Not a terribly huge deal - just a pain in the ***.

 

Try a MAP gas torch. That will make the pipe glow cherry red and it should come right out. It burns MUCH hotter than propane.

 

True, try to get it cherry hot, once it breaks loose dont just keep backing it out, this will aid in destroying the threads, Back it off in and out, like turn it say 1/4 inch out then back in, then go out 1/2 inch then back ect, I have found this method helps in saving the thread, then like said, use a thread chaser..

 

Get it hot then squirt it with a 50/50 mix of acetone and ATF. You might also try tightening it a little first to break the thread seal. Good Luck!!

 

Id soak it in deep creap penetrating oil for a day, cut the body off after letting it sit, heat it with a map gas torch till red hot and use a good 6 point socket or wrench to take it off. Do what moe said and go 1/4 out and a little back in so it doesnt fubar the threads.

 

If you aren't, use a six point deep well socket. You'll have to cut the wiring off the O2 to do so. Because of the slit in the O2 socket it will not handle the kind of torque needed and will expand and start rounding off the edges of the sensor.

 

For what it is worth, if you do have to cut it off and drill it, I have the HeliCoil kit to re-thread the bung. You'll have to buy the thread-set, but I'll send you my kit with the install tools and bit. You pay shipping to/from and a deposit.