Where would the O2 sensor be on a '91 Legacy LS ?

[Legacy Wagon]

Since it really sounds like my O2 sensor has gone south I'd like to explore the idea of pulling one of a wreck. There's a yard very close to me and I have a few days off, its starting to get cold out so the sooner the better.

- Anyone have a diagram or picture showing the location of the O2 sensor ?

- What tools are required ?

- What years will work with my '91 AWD LS 5sp wagon ?

thanks !

[vrg3]

It's not a very good idea to use a used oxygen sensor. It's liable to be in just as bad shape as your current one. The only exception I'd make would be if you know it was very lightly used (I have one on my car that was pulled off an '03 Kia in a junkyard). Even then you still should at least get a new 18mm steel crush washer to help it seal.

On non-turbos, I think the sensor's right where the exhaust from both cylinder heads meet, kind of behind the engine crossmember.

The sensor has a 22mm hex base so you can use a 22mm or 7/8" wrench on it. If it's hard to remove, an oxygen sensor socket can help; it's a deep-well 22mm socket with a hole cut out of one of the sides so the wires can hang out of it.

Most oxygen sensors should fit your car, but you'll have to figure out which wire is which and splice it in correctly. But if you want it to plug right in, I think it has to be for 1994 or earlier Legacy or Impreza.

[Legacy Wagon]

Ok, its one of "those" parts that's usually better bought new. The part is around $200 Cdn so I thought I could save myself a little money but if you figure its probably no better than the last one there's no real point.

Are there any decent online parts places for Subaru that sell OEM at discount ? I've done this for my VW and its much cheaper to buy from the US even after paying shipping. thanks

[vrg3]

Well, if you can find a lightly used one, go ahead... but yeah, I wouldn't use a sensor pulled off a ten-year-old car.

There are several online Subaru discount dealers, but I don't know if any ship to Canada:

http://www.subaruwrxparts.com/
http://www.subaruparts.com/
http://www.autowebaccessories.com/
http://www.allsubaru.com/
http://www.1stsubaruparts.com/

You can get an OEM-style sensor from http://www.oxygensensors.com/ for $70 US, and that'll plug right in.

Or you can actually get a universal 1-wire sensor from the same site for just $20 US (look it up for a 1992 Mazda 323). You'll have to splice the wire in, but the sensor will work fine after it warms up.

[totech]

Where up here are you? Several of us are around..

[QuickDrive]

Word

[scottzg]

Could one wire the heating element of the old sensor into a 323 sensor? I admit it, im a cheapass.

[vrg3]

I don't see how... I've never tried to take apart an oyxgen sensor before, but I doubt it's really serviceable.

Anyway, the heater usually dies long before the sensor itself. Cracks form in the heating element. I'd bet most board members who still have their OEM sensor are driving around with an unheated oxygen sensor. I know I was.