Hi Folks
I need help - I am setting a P0420 code, hit the CATs with a Mallet – no move material, the CAT sounds OK. I replaced the back O2 sensor, was a pain but I did it. The upper O2 sensor will not move. I am using a O2 Socket with a 1” long wrench to turn it but no luck at all. I am applying enough force that I feel the socket is spreading apart but O2 sensor does not move. 97 Z-28 with 117K on it. Somebody that has done this before, any ideas on how to get the SOB out.
Thanks
Bill

PS: I want to replace the O2's first - if that does not fix it than the cat.

 

get some P-Blaster at Advance and soak the threads.

 

you have to use some penetrating lube that u can buy at local auto parts store. helps to break the rust...............

 

Hi Folks
I have been using Liquid Wrench but I need to try P-Blaster. It appears to be the choice of everybody here. I have never heard of it but live and learn.
Thanks
Bill

 

My local Wal-Mart has P Blaster, believe it or not.

 

I had to heat the pipe around the O2 sensor until it was loose. PB blaster had no effect, although I didn't leave it overnight, just an hour or so. If you heat it with a torch or something, just make sure you get it out fast before it starts to expand as well and gets stuck again, lol. Good luck.

 

yea those threads on the O2 sensors are probably the nastiest and hardest to get out, they corrode so much because of the heat and vapor that passes through, what I did was drop the Y, that made it much easier. I did it before with the Y on and I did it but it was a pain

 

PB Blaster has to be the best thing ever for removing rusted nuts and bolts.

 

Removing the ypipe bolts is probably just as tuff lol

 

Hi Folks
I purchased P-Blaster and sprayed the O2 sensor. I waited a while and tried to remove it - the O2 socket was giving and spreading at the bottom.

THIS WORKED: I cut the 4 wires off the O2 sensor and used a deep 7/8 socket with a 18 breaker bar - there is room. That O2 sensor came right out, not a problem. The breaker bar gave the leverage I needed and with the help of P-blaster. Most cases the O2 is bad anyway, so cutting wires isn't going to hurt.
Thanks for the help - I drove the car and I am not setting the P0420 anymore, replace both drivers’ side O2s. But I wait to see what happens over the next week.
Bill

 

Did you put any hi-temp anti-sieze on the threads of the new O2 sensor?

 

YES - however, I hope I never have to pull them again Ha, Ha.
Bill