So I was trying to install a testpipe, the o2 sensor on the cat seems not coming off no matter what I do. I have even used WD-40 spray. So how did you guys take if off, or I just don't have enough strength?

 

It's probably a good idea to work out in the weeks/months beforehand so you have enough strength to undo a bolt.









jk.

Get some Kroil or another good quality thread penetrating lubricant, then put it on and let it seep in for a few hours and do it's magic. Come back and give it another shot. It does take quite a bit of force sometimes.

Also make sure you're turning it the right way.

 

Heat that *****... that what i had to do. i got some map gas and heated it until it was glowing...

 

Penetrating oil and leverage. Put a pipe over the end of the wrench. Make sure it has a good grip on the O2 nut before you apply force.

 

Also it helps to use a slotted deep-well socket instead of just trying to wrench it from the sides. You will get better contact on all sides. Slotted on the side so the wire can hang out of the side while you're turning it. Expect the threads to be morphed from the heat. I've taken mine out a few times and I swear I don't know what it's still grabbing on lol. It looks like a mess of distorted threads! Good luck.

Oh and remember, lefty loosey!

 

Is it possible the sensor and the cat has been melted together from the heat, so by applying brutal force it's going to cause damage to the sensor?

 

i just sprayed some kroil on it. Put on the wrench and went at it with the hammer.

No they are not melted together. You would need an extremely high heat source. Just make sure you have a good bite with the wrench. You dont want to strip it.

 

use this kind of wrench => http://cdn3.ioffer.com/img/item/120/745/041/fvfB.jpg

use this spray (pb blaster) => http://blasterchemical.com/display.cfm?p=50003&pid=4


Steps:

1. heat car up
2. spray PB Blaster on bolt
3. let spray sit for 30 mins
4 spray pb blaster
5 loosen bolt with wrench

You may need to let the spray sit longer and repeat heating and spraying. Eventually it will come off.

 

Many rear O2 sensors have been crossthreaded from the factory, which is probably the case. I would not advise heating up the area with a torch otherwise you might damage a 300 dollar sensor, which has to be replaced with a OEM one.

Using something like PB Blaster etc... will work well probably to help loosen thing up.

I suggest getting a $5 dollar O2 socket from the auto parts store and then using a large breaker bar to remove it.

Once you get the O2 sensor out, put some anti-seize on the sensor so if in the future you have to remove it, it will not be seized in there.

 

1.) Spray around the socket part of the o2 sensor with PB blaster then go do step 2.

2.) If you dont already have one, go to your nearest autoparts store and get a o2 sensor socket. Make sure ou get a 1/2" drive o2 sensor socket.(Wait for the PB blaster to do its work)

3.) After waiting about 30 minutes or so, get under there and try to break it lose with the o2 sensor socket. It should work pretty easy.

BINGO

 

i have one for sale if anyone is interested

back on topic

spray with some penetrant let it work for a while and then unscrew it

 

Thanks for all the ideals. I have been running without the o2 sensor for 1 week. The ecu gave me a CEL right away. I am probably gonna try the PB Blaster spray and o2 sensor socket one this weekend. Hoping it works....

 

didnt know they made a special wrench of a 02 sensor. learn something new everyday.

 

Yup, its a cheap socket that works great!

 

Very interested, Threads Took a fall on mine,

Pm me