changing oxygen sensor

[the5tolls]

Hi Guys, Who can tell me what it takes to change the oxygen sensor, I don't even know where it is located. Thanks for any advice! Bill

[the5tolls]

it is an 89 with a carb

[GenevaDirt]

You can get a socket designed to take out the sensor if you want but where it is located is easy access so I would not worry about it. I cut the wire and use a regular socket...then use a wrench to install. Should be located in the front of the engine right on the exhaust manifold.

[TominMO]

The O2 sensor is in the exhaust manifold, and looks sort of like a large spark plug. You can go buy a special socket with a cutout section in it, to accommodate the wire; or, you can just disconnect the wire first and stick a 7/8" box wrench over the hex on the sensor itself (running the wire thru the box wrench).

If it's hard to get out (i.e. no anti-sieze was used before), try tightening it a little to help break the rust. Also try tapping the wrench with a hammer, because the vibration will help. As will PB Blaster. When you put the new one in, use anti-sieze. The new sensor may already have it on the threads.

Edit: Holy redundancy, Batman!

Rock Auto lists the Denso part #234-1019 for ~$22. But you can go to a McParts store and buy the 234-1000 for ~$14. Same sensor but you need to splice onto the old sensor's wire.

[rmoltis]

I just take my open adjustable wrench.
Or
Crescent wrench
And then no need for special sockets or cutting wires.
Just match up the hex size and twist.

One time it was hard to remove so I hung the crescent wrench on the hex.
Then smacked it with a sledgehammer.
Worked right away.

[GenevaDirt]

I just take my open adjustable wrench.
Or
Crescent wrench
And then no need for special sockets or cutting wires.
Just match up the hex size and twist.

One time it was hard to remove so I hung the crescent wrench on the hex.
Then smacked it with a sledgehammer.
Worked right away.

Have to cut the wire to put the new one in....just saying.

[TominMO]

Have to cut the wire to put the new one in....just saying.

Unless he bought the one with the OEM plug already on it.

I can't recommend using an adjustable wrench; too much chance of rounding the hex on the old sensor. You got lucky, rmoltis.

[GenevaDirt]

Unless he bought the one with the OEM plug already on it.

I can't recommend using an adjustable wrench; too much chance of rounding the hex on the old sensor. You got lucky, rmoltis.

who wants to spend that much money....we are driving Festy's....we are cheap!

[zoom zoom]

Festiva manifolds are a little trickier, the cast manifold likes to interfere with any wrench you try to put on it. Even with antiseize they usually take a lot of torque to get them out in my experience. The one I just put on my b6 swap 1500 miles ago didn't want to come out without the help of a 3' cheater bar on a breaker bar. The longer the handle is the easier it will be. Def want a socket for those things, one day I'll own a nice one with a slit on the side specially made for them.

[TominMO]

Festiva manifolds are a little trickier, the cast manifold likes to interfere with any wrench you try to put on it. Even with antiseize they usually take a lot of torque to get them out in my experience. The one I just put on my b6 swap 1500 miles ago didn't want to come out without the help of a 3' cheater bar on a breaker bar. The longer the handle is the easier it will be. Def want a socket for those things, one day I'll own a nice one with a slit on the side specially made for them.

I own two of those sockets--because I couldn't find the first one when I needed it. Found it a couple weeks after buying the second one, of course.

At least on the Festy & Aspire manifolds, the sensor is on the pass. side. On my B6 Festy, it's on the driver side near the rad, so a bit harder to deal with.

On my Aspire, I actually had to go buy another exhaust mani from a JY because the O2 sensor threads were too far gone, from a previous mechanic's cross-threading it. But now all fasteners are anti-seized, which will be helpful when I install Matt's header today or tmw.

[jason_]

On my Aspire, I actually had to go buy another exhaust mani from a JY because the O2 sensor threads were too far gone, from a previous mechanic's cross-threading it.

I had rusty threads. Ground out the old one, welded in a $3 bung. Standard sparkplug threads.



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[the5tolls]

thanks for the help guys, I am headed out right now to look over the situation, I am hoping that the exhaust shield does not have to come off, those heads are so rusted I don't know if it is possible. Bill

[jason_]

thanks for the help guys, I am headed out right now to look over the situation, I am hoping that the exhaust shield does not have to come off, those heads are so rusted I don't know if it is possible. Bill

Get them white hot with a torch. Beer swig. Then a dark red hot, they'll wrench out like butter. Done it a million times. Twice from bolt head chases heat down to threads, it'll swell, then relax and shrink, busts rust loose, and spin out with no effort.

Honestly they'll spin so easy you can bite them with a good pair of vise grips. I did it on 1 of mine. Or weld a better nut on the top. 2birds one stone on welding. Welds pull and shrink when they chill. And you'll have a new hexhead to wrench on.


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[the5tolls]

well I found it, that was easy enough, looks pretty rusty, I followed the wire and the plug was disconnected, I am guessing someone thought that would make the check engine light go out. I am going to order one in the next few minutes and will probably try and install in about a week. Thanks again! Bill

[Spike]

Something else I've seen done - worked for me - run the car until it's middle-warmed up.

I tried for an hour to get it out when the car was cold.. warmed up, one full-body shove on the breaker, and it came free. Just don't burn yourself!

-Joe