I had a code 44 (Lean Exhaust), so I looked under the engine and the O2 sensor had broken off the manifold. The threaded part was still in, but the actual sensor had broken off. I JB Welded it back on and the 44 stopped but code 13 (O2 Sensor) came on. So, the sensor must've gotten damaged as well. I went out and bought a new sensor and loaner sensor sockets from AutoZone. Here's my question: HOW THE HELL DO YOU UNSCREW THE DERN THING OUTA THERE? I know it must be heat-fused to exhaust manifold. I used a cheater bar and everything to get as much leverage as possible but it seemed like i was gonna break my ratchet before the thing came loose. I know people out there have replaced O2 sensors. How'd you manage it?

 

You have got to be Kidding me?

Yeah, Time for a new one.

try soaking it in WD-40 over night. Your just gonna have to stop pussifying it, and Get down to buisness.

What do you have to loose... its already broken )

 

Hey, it said lean exhaust, and the sensor was just flappin around in the air. I figured, well, air is pretty lean, might as well stick it back on there!

But yeah, i'll try soakin' it in some kind of panther pi$$ overnight. It'd also help running the engine up to op temperature before tryin' to muscle it off right?

 

LOL well at least your thinking... thats a step above 90% of the people on here.


hahaha Yeah Busting it off might be easier at operating temp )

 

they make a socket for the 02 sensor. you might want to warm the engine up and get a breaker bar.

 

Read, it does a body good.

 

Run the car for a few minutes to get the exhaust heated up, then take a 7/8" wrench and try from below. That's how I got my stock one out--it's tricky getting the wrench on there, but you can do it. I guess you could use the socket as well, but I have a more difficult time getting good leverage with that thing.

 

I just pulled one out of my 85. I used a sensor socket and some long extensions to get the rachet handle by the power steering pump for leverage. I sucket some manifold threads with it and am now doing a helicoil. If you get there, they have one for O2 sensor holes ( 18mm x 1.5mm ) Expensive but is available.
Bob

 

Thanx guys. I'll give it another whirl tomorrow...

 

i am having the same problem i can't even get a wrench on it. i didn't know about this "sensor socket" but i'll go try to find one.

 

i also wouldn't run the car

when the metal heats up it expands. now this is in a hole when you heat up a peice of meatal with a hole in it, the metal will expand and make the hole smaller, thus making it even harder to get off.

 

No, when the metal expands the hole gets larger, and the cast iron that the manifolds are made from has a higher expansion coefficient than the metal that the sensor body is made from, that is, it will expand more than the sensor body under the same heat conditions.

 

r u serious?

It does not matter which one of the materials expand more. the cast iroc manifold is going to make the hole smaller when it is heated up, the ideOF MEATAL EXPANDS WHEN IT GETS HOT IS TRUE, BUT NOT WHEN ITS GOT NOWHERE TO EXPAND TO. THE ONES PLACE THAT IT DOES HAVE TO EXPAND O IS OUT. AND THUS MAKING THE HOLE SMALLER. MEASURE THE HOLE HOT AND MEASURE A HOLE COLD. THE SAME HOLE WILL BE LARGER WHEN IT IS COLD.

 

Mine needed replacement a short while back, and did not respond to the usual work (Deep Creep + an hour, WD + another hour, jumping up/down yelling, crouching atop a breaker bar, etc.) I fired the car up after remembering how my Physics Instructor hit the class with the "Does the hole become larger or smaller?" question, and then explained the whole shebang. FWIW I was wrong then...didn't pay nearly enough attention...but there was this girl in the front row....never mind.

The early-1990s aside, I fired up the 'Bird and waited a few minutes. Once "Awake" had finished playing I cracked out the ratchet. Voila`, el-sensoro-unstucko.

HTH, peace

K

 

Go to a shop where they assemble jet engines, tell me what they do.

 

i'm not gonna sit here and agrue with you guys i know what ur saying and i know what morley is saying too. but it works for all the wrong reasons.

the hole does get smaller and i'm ot gonna waste my time going to a jet shop.

morley is right about the two changing at differnet rates. the cast iron does change ata difernet rate as the sensor and there for that is why it works. your seperating and causing the metal of one to change rather than both of them. but f you acutally think aboutit you'll understand what i'm saying.
if he wants he can try it both ways and see what works. making it hot most lily will work but theres a greater chance of messing something up.

i'm not coming back to this thread just cause i don't have the time to sithere and agrue over something so not important. nor am i coming back to this thread-
because this will just become a gaint circus and nobody will get the real reson of something working. .

oh and this is just a samll block chevy not a jet engine

 

No, it works for all the right reasons. I used to build jet engines. To install the bearings we would freeze the bearings and then immerse the piece they were going into in a bath of hot oil (200-300*F, then take the frozen bearing and press it into the piece. If you didn't heat the part the bearing was going to sit in it would never go in, not with a 50,000 lb hydraulic press. Why? Because the metal of that piece had expanded and "pulled" the hole to a larger dimension. The same would go for freezing a part with a hole in it, it gets smaller.
A simple test, Drill a 1/2" hole in a piece of metal, use a trimic to make sure it is exactly .500", next put it in an oven at 200* for a few hours. Take it out and remeasure the hole, it will now be .502-.503" Next put it in liquid nitrogen for 10 minutes, your hole will now measure .497-.499" GUARANTEED! I do this for a living, I think I can speak from experiance on this.

 

Heat that sucker up, but be careful you don't burn yourself getting it out.

Oh, and make sure your new sensor has anti-sieze on the threads. If it doesn't don't put it in. Permatex sells small tubes of anti-sieze for just this purpose. Put it on the threads, be careful not to get it on the sensor "bulb", this will contaminate the sensor. If you do get some on the "bulb" you should be able to remove it by soaking the sensor "bulb" in acetone for a few minutes. Let it air dry and then put it in.

Good luck, wear gloves when removing that sensor too, I hate busted knuckles.

 

Agreed, run it for a minute or two to heat up the manifold, it will come out much easier. Simple physics. Not a physics major here, just lots of experience. It works, bottom line. Done. That is all.