I just bought a new O2 sensor to put in the truck as the one in there is surely the factory original. I spent about half an hr striving with it but was unable to loosen it. I tried the giant crescent wrench but that was just rounding off the flats. tried the vise-grips and that was just tearing the thing up. The frame rail, radius arm and the rest of the exhaust make it a bit awkward. The way I see it, here are my options:

1) cut the wires and get a deep socket (looks to be about 13/16"?) with the big breaker bar on there

2) saw the sensor in half and get a regular (not deep) socket on there

3) attack it daily with PB Blaster for a few days then try again w/ visegrips, possibly assisted by blowtorch

4) PB Blaster combined with socket approach

Anyone else done this job? any hints?

 

You can try any of those. You could also drop the exhaust for more room.

 

how about a 18mm wrench.....

 

it winds up being 7/8". I picked up one of the special O2 sensor sockets with the slot for the wires... did not work, just stretched open enough to allow the hex to slip around tomorrow I'll be cutting the wires and getting it with a regular 7/8" socket and of course more PB Blaster. Can any harm come from driving the truck with the O2 sensor unplugged?

 

I don't think so on my 89 I just cut mine off lol

 

there wont be any damage but if its the 02 behind the cat (if you got that one) it will show a check engine light for the cat being bad. if its the one before the cat then you will lose mpg/power.

 

it's before the cat... not that I have cats on the truck anyway lol

 

Welcome back exec, take a torch and heat up the bung but not the sensor. Works well for me.

 

got the bastage out! had to break off the end of it and get a real socket on there, but it didn't even need the pipe on the breaker bar!