I'm trying to remove my stock cat but I can't get the o2 sensor loose. How did you guys remove it? Can I spray some liquid wrench on it or will it mess up the sensor?

 

When we had that problem...we doused it with WD-40....and since the 02 sensor remover tool we had got lost...we clamped the 02 down with a set of visegrips and took a hammer to it....and it eventually popped out....

I know we are gonna get the barbarian award of some sort for that one....but the sensor still works good..and the it is barely knicked from the visegrips....

Another method we found that works is if you grip the cat down on a bench vise and use a monkey wrench....(or more commonly known as a pipe wrench?? plumbers use?) and the added leverage of the handle really helps here....

HTH....

 

Thanks for the tips. How did you get the cat to a workbench? My o2 sensor wires go directly into the car so I can't unplug it like the primary o2 sensor. I guess I'll try the hammer approach.

 

i had the damnedest time getting the O2 sensor out of the cat as well . . . my angle was terrible! so i ended up pulling the cat down as far as i could (exhaust was disconnected), and then i was able to get an adjustable wrench on there (a big *** one, too! ), and while it was on like a ****, i did eventually get it off . . .

good luck! the key is leverage, and a lot of it!

 

eric (nab20c5) prefers the "monkey wrench" method as well...

Make sure you use some anti-seize when you reinstall... h

 

So I should leave the cat bolted up to the B pipe right? This all better be worth it.

 

I used the big-*** adjustable wrench as well. 'Tis a pain in the ***, anyway you look at it.

 

<monty python voice>

"yes, 9 out of 10 mechanics agree that the big-*** adjustable wrench is the right choice."

</monty python voice>

 

well, that and a big ******* hammer.

 

actually smart mecahnics prefer heat...heat it with a torch and it will come right out with the right size wrench.

and as much as you think your 02 sesor doesn't unplug, it does...they all do...pull the rubber seal out from the floor of the car and you will find the plug tucked up inside...

dw

 

throw it in a vice, saturate it in wd40 , then crank her loose! That doesn't work take out the big arsenal, show that sensor who's boss.

 

Use anti-sieze when you put it back in. Soak it in WD-40 and let it sit for an hour, THEN try it.

 

as davew mentioned above me....it is possible to unplug the O2 from the car so you can unbolt the cat and take it to a workbench....

it's much easier than screwing around under the car (especically if you don't have a hoist-a-helpin'!)

and YES...antiseize it before reinstallation!

 

yeah, well dave, i didn't have a torch. and my mechanic-abilities ain't quite what yours are, so . . . i thought i did rather well.

 

I didn't have a torch either, but the WD-40 worked. I dropped the hangars from the b-pipe, disconnected the muffler and let it drop. No problem taking off the 02 sensor with the cat still attached to the b-pipe. Took some "convincing" (love taps) also, but it came out and went back in without issue.