FAQ: O2 (Oxygen) Sensor Information

Another suggestion I have is to buy/borrow an O2 socket. It's one of those things that you'll use once, but it's so awesome to use and it saves so much trouble. Try to get a half inch drive one, or get one to match whatever drive your biggest breaker bar is.

Do you get to the upstream sensor from the top? It looks a bit crowded, so I wasn't sure where you came from to get to it.

Yep, go back a page or two and you'll see exactly what I used. It's a bit of a tight fit, but it goes:

O2 Socket
Universal (wobble extensions probably don't have enough give to work)
Lots of extensions - at least 2 feet of them. You'll have to snake them through everything behind the engine. It's tight, but doable.
Breaker bar - I used my giant torque wrench. Sears has them marked off to 40 bucks here, and it works great as both a torque wrench and a breaker bar.

matt270avian wrote:

Denso is the way to go. Sensor 2 means it's the post-cat sensor, but you might as well do both since they're not to expensive. Might be cheaper on Amazon.

Where is the 2nd sensor at?

Do I need anything besides the sensors (special tools, gaskets, etc?)

2nd sensor is right after the catalytic convertor. Aside from tools and the sensor itself, I don't believe you need a gasket, but they give you some copper RTV or something like that.

Also, make sure you don't touch the end of the new O2 sensor.

KnottyEagle wrote:

2nd sensor is right after the catalytic convertor. Aside from tools and the sensor itself, I don't believe you need a gasket, but they give you some copper RTV or something like that.

Also, make sure you don't touch the end of the new O2 sensor.

If that's the 2nd sensor, where is the first sensor? The one between the cat and the resonator is the one I looked at earlier.

Jack the R wrote:

If that's the 2nd sensor, where is the first sensor?  The one between the cat and the resonator is the one I looked at earlier.

The first sensor is just off the back of the engine mounted in the DP. If you look straight down the back of the engine it will be just to the right (closer to the brake booster) "under" the spark plug wire.

Whomever informed Knotty not to touch the O2 end is a moron. It's not a freakin light bulb....

Abaddon wrote:

Whomever informed Knotty not to touch the O2 end is a moron. It's not a freakin light bulb....

So I'm not the only one that thinks that was stupid?

KnottyEagle wrote:

So I'm not the only one that thinks that was stupid?

No!

My 02 sensors came in, let me make sure I have this correct - Upstream is behind the engine, downstream is between the cat and resonator?

Yup. Upstream is before the cat, downstream is after.

Thanks, I'll go get that done.

There's a packet of goo with the new sensor - where does it go? Threads, washer?

My old sensor is stuck on good too. Is Knock'r'loose usually enough to get these off, or do I need to heat it?

Jack the R wrote:

There's a packet of goo with the new sensor - where does it go?  Threads, washer?

My old sensor is stuck on good too.  Is Knock'r'loose usually enough to get these off, or do I need to heat it?

As long as it's trash anyway, i'd cut the harness off it and use a full deep socket for the best grip and use penetrating stuff. Heat and beat as needed. The paste with the new sensor is basically antiseize so yeah, wipe some on the threads and washer - save the rest.

turtleman wrote:

As long as it's trash anyway, i'd cut the harness off it and use a full deep socket for the best grip and use penetrating stuff.

That's a good idea. It's a big "nut" though, I'm not sure I have a socket for it.

What does it need to be torqued down to?

FWIW, I busted a craftsman end wrench trying to get an o2 sensor out. I would 100% recommend buying an o2 sensor socket.

Sir Psycho Sexy wrote:

FWIW, I busted a craftsman end wrench trying to get an o2 sensor out. I would 100% recommend buying an o2 sensor socket.

Not a bad idea - what size?

I can't remember... I wanna say 7/8 or something. I think o2 sensors all use the same size socket for the most part.

Sir Psycho Sexy wrote:

I can't remember... I wanna say 7/8 or something. I think o2 sensors all use the same size socket for the most part.

Yep

Well it has been heated and I've torqued on it enough to round it off and it hasn't budged. I'm out of ideas, other than to take it to someone with a lift. The car will run fine without the sensor, right? Cause I tore up the wire pretty good.

Jack the R wrote:

Well it has been heated and I've torqued on it enough to round it off and it hasn't budged.  I'm out of ideas, other than to take it to someone with a lift.  The car will run fine without the sensor, right?  Cause I tore up the wire pretty good.

It's probably welded itself to the pipe. The only thing you can do is take it to someone and have them remove it if possible. Hopefully the threads don't come out with it....

The car will run fine with the rear sensor inop, yes. The SES light will come on though.

Abaddon wrote:

Jack the R wrote:

Well it has been heated and I've torqued on it enough to round it off and it hasn't budged.  I'm out of ideas, other than to take it to someone with a lift.  The car will run fine without the sensor, right?  Cause I tore up the wire pretty good.

It's probably welded itself to the pipe. The only thing you can do is take it to someone and have them remove it if possible. Hopefully the threads don't come out with it....

Brilliant - is there a better option? Can that piece of pipe be replaced easily or is it going to be welded in place too? If I take it to a mechanic and he pulls out the threads, than I'd either be in worse shape than I am now (at least the 02 sensor hole is plugged) or I'd have to replace that pipe to get new threads.

Does the upstream sensor weld itself in place too?

You can get a new downpipe from zzp, but they don't come with bungs welded on.

matt270avian wrote:

You can get a new downpipe from zzp, but they don't come with bungs welded on.

Is there a more sane option than "ignore SES light and forget about it?"

Jack the R wrote:

matt270avian wrote:

You can get a new downpipe from zzp, but they don't come with bungs welded on.

Is there a more sane option than "ignore SES light and forget about it?"

A new catalytic converter has the bung.  I replaced mine recently with this one (walker 15817)

http://www.rockauto.com/getimage/getimage.php?imageurl=http%3A%2F%2Fwww.rockauto.com%2Finfo%2FWalker%2F15817.jpg

and transferred my O2 sensor to it.

You can also cut out your current bung and just weld a new one in.

http://www.ebay.com/itm/O2-Oxygen-Sensor-Nut-Bung-02-M18-x-1-5-THREAD-/180846024262?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a1b435646&vxp=mtr