o2 Sensor Replacement

[MTCFORUM]

I'm wondering if anyone has any input on the best way to go about changing these.

I have heard everything from "it's Impossible" to "it's easy" and includes needing to bend a custom wrench or dropping the exhaust....

Can anyone give any input? I need to do this. I looked at it briefly and it didn't look real easy....

Thanks!
Scott

[MTCFORUM]

Both have to be done from underneath the car. No custom-bent wrench is required and lowering the exhaust only helps on the passenger's side.

Driver's side: Use a crow's foot and at least a 9 inch extension to break the sensor loose. (Helps if the car is cool.) The wiring is the tough part with this one, so having skinny arms is a definite plus. Along with the actual connector, there's a wire clip that goes into a hole in the engine block to hold the wiring away from the exhaust. Not a total nightmare if you're good at doing things by 'feel' since being able to see what you're doing at the same time you're doing it is nearly impossible.

Passenger's side: Easier if you can lower the exhaust to get the cat out of the way. A U-joint (or wiggle) helps with the exhaust bolts. Either the crow's foot or an O2 socket (has a cutout for the wires) will work once the exhaust is down. The wiring on this one is nowhere near as bad.

Hope this helps.

[MTCFORUM]

Yes, that's good information. Thanks.

On every car I have ever worked on before, the exhaust bolts have been rusty and nearly impossible to remove. Am I likely to encounter that on my car? She's a 95 with 84K miles and alwasy been in cali. If so, is it possible to do it without dropping the exhaust? I would hate to break a bolt off on the exhaust. That would really suck....

2nd question, and this one is the "bone head" of the week question.

What is a crow's foot and how more or less does one use that? I have a picture of one in my head, but no idea how to use it...

Thanks again,
Scott

[MTCFORUM]

Well, my exhaust bolts were removed with air tools, so I don't know how stuck they were. I'm sure you can do it without lowering the exhaust, but it sure is a lot easier if you can.

A crows foot is just an open-ended wrench with no handle and with a square hole for a ratchet extension. It's only used to get in tight places as it can only be turned less than 1/4 turn at a time before needing to be repositioned.

Here's a picture: <A HREF="http://store4.yimg.com/I/toolsplus_1676_4887680" TARGET="_blank">http://store4.yimg.com/I/toolsplus_1676_4887680</a>

[MTCFORUM]

Thanks. That makes sense now. Do you know off hand what size those things are? I'd like to pickup a crow's foot before I dig in.

Scott

[MTCFORUM]

7/8. Go to Sears, Home Depot, or Lowe's if you don't want to end up buying a whole set like I did.

[MTCFORUM]

If you do decide to drop the exhaust on the passenger side, I wouldn't be too woried about rusty bolts. Mine had a fair amount of surface rust on them but still came off pretty easy. For that side I used a 15mm deep to 3" ext. to "U" joint to 10" extension. Came right off that way! Let me know how it goes.

[MTCFORUM]

If you drop your exhaust, it would be a good idea to pick to some stuff called "Never Seize" and coat the studs before removing the nuts. Coat the studs again before installing the nuts when reinstalling. That way you shouldn't have a problem there, ever. I always use Never Seize on my spark plugs, wheel lug studs and any area that may have a problem down the road. I never have a problem , at least not after the first coating. I think Discount A.P. or Pep Boys carries it and it's not expensive. I would also coat the threads on the O2 sensor.

[MTCFORUM]

Thank you for all the great help. I am wondering if I need a gasket for the exhaust, since it seems like it will be easy enough to take off...

Oh, and that never seize stuff is good. I bought it for my spark plugs. Never tried it on lug nuts, though....

Scott

[MTCFORUM]

No gasket on the exhaust that I'm aware of. The pipe's kind of tapered so it's a real tight fit once the bolts are tightened. Oh yeah, the O2's come with anti-seize already applied to the threads, so be careful when handling them.