removing a seized o2 sensor

[jpdoane]

I spent all afternoon yesterday trying to wrench out my O2 sensor. I've got a V6 - its the one behind the engine, next to the firewall, so no good leverage. I made sure the engine was hot when I tried (not fun BTW). I even attached a rope to the ratchet and pulled on that.
I'm afraid it might be seized. Any advice on getting it out?

-Frustrated Jon

[HATEnFATE]

Spray it with some sort of a rust penetrant. even WD-40. get it soaked and let it sit for about 15 minutes.

[Camryamnesty]

a breaker bar, piece of pipe works wonders. Get some PB blaster, and spray that on there.

Are you replacing the sensor? or what?

[Hajoca]

If you are going to reuse the sensor, spray oil carefully. oil on the breathing holes of the sensor will kill it.

In the past, I warmed up the exhaust pipe, and non flammable brake cleaner shot onto the O2 sensor nut to shock (shrink) it.

[YESCA]

You could always use a torch and heat up the pipe around the o2 sensor, take a wrench and breaker bar and gently twist it out. I watched the muffler shop do that with my stock exhaust when I had my cat-back installed, and they were able to reuse it as well. What i saw was that they heated the pipe till it was red hot and they unscrewed the sensor. but if you do not have access to a torch, WD-40 and a breaker bar will do just fine. You will just have to let the WD-40 sit for a bit so it can soak through.

[thoughthard]

Originally Posted by Camryamnesty

a breaker bar, piece of pipe works wonders. Get some PB blaster, and spray that on there.

Hit it with PB Blaster, let it soak overnight, reapply next morning, begin work that afternoon.

[Digger1]

Originally Posted by Hajoca

If you are going to reuse the sensor, spray oil carefully. oil on the breathing holes of the sensor will kill it.

In the past, I warmed up the exhaust pipe, and non flammable brake cleaner shot onto the O2 sensor nut to shock (shrink) it.

Haj,
Cool trick.....thnx!

[zoni]

Originally Posted by YESCA

You could always use a torch and heat up the pipe around the o2 sensor, take a wrench and breaker bar and gently twist it out. I watched the muffler shop do that with my stock exhaust when I had my cat-back installed, and they were able to reuse it as well. What i saw was that they heated the pipe till it was red hot and they unscrewed the sensor. but if you do not have access to a torch, WD-40 and a breaker bar will do just fine. You will just have to let the WD-40 sit for a bit so it can soak through.

The exhaust manifolds are subjected to the most heat in the system... therefore the expansion and contraction of them tends to form a TIGHT grip on O2 sensors... its often very difficult to get the sensors out without damaging them on an unheated piece.

THE BEST WAY is to heat the fitting with a torch. OR if the manifold is still on the car.. run the car un to operating temp for a few minutes, and then take it off with the manifold HOT. careful with your hands, wear gloves, and you will be all set.