89 F250, with 7.5L engine.

Okay, I know it is on the exhaust manifold. But I just cannot find it. I looked at both sides, and from the bottom, as well as from the top. Haynes/Chilton's are ambiguous and the FSM doesn't say which side, seems to vary based on the engine.

 

Just follow the exaust manifold down a bit and there should be wires comming out of it, it's pretty easy to see. I can take a picture of where mine is on my 4.9L if that would help.

 

I will have to get it on ramps, it is pretty hard to crawl under there.

If I find it -- I can replace it. I plan to soak it in PB Blaster for a day or more. I think it is original and 15 years old. (85,000 miles).

 

I found it. It is not at all where the FSM said it would be. It is way down near the cat! Not near the engine.

Looks like the regular open end wrench won't get to it. In addition to the socket, will have to use some kind of bent open end wrench.

 

I have heard that it is easier to change the O2 sensor if it is hot, or at least warm. Wear gloves, good luck.

Frank

 

Also there are special O2 sensor sockets if you have a hard time with regular wrenches/sockets.

Man I really need to change mine out too LOL

 

You don't need that special socket taking it out --- you can cut the wire and use a regular deep 7/8" socket. But it looks to me like based on location of this O2, I will have to use that special socket putting it in. Maybe I can get away with using a bent open end wrench.

I would rarther not, as it is a single-purpose tool, useless for anyting else.

 

On my 96 I replaced the O2 sensor without the use of any special tools. If I remeber correctly I just used an box wrench to remove it after I cut the wires for the sensor. To install it just use the open ended side of the wrench after getting it in finger tight. Some anti-seize helps on the install. It has been awhile since I did this so the above procedure may not be exatly correct but I don't have any special tool, of that I am certain.

 

If you use anti-sieze, use the stuff SPECIALLY FOR O2 sensors. It needs to be conductive, and not wreck the sensor. Regular stuff should not be used. Cheers.