[crackie]

I don't have the special Alfa tool for removing the oxygen sensor. Imagine most of us don't. But also guessing I am trying to remove it the hard way and someone can set me straight.

After looking at disconnecting the exhaust down pipes from the manifolds to get some clearance to get at the O2 sensor, I decided it would be easier to hacksaw off the top of the sensor to get a socket on it. It's possible to cut, but it'll take awhile. I am guessing there is an easier way.

Any suggestions from those who have traveled this road? Also, does anyone know off-hand the size wrench needed to remove it? Bet I could get an offset box-end wrench for it and that might be the way to go.

No clue why Alfa put a collar around the wrench-end of the sensor. Seems unnecessary.

FWIW - you can get OEM Bosch sensor on Amazon for ~$75.

Thanks.

 

[alfaparticle]

I bought a generic O2 sensor tool from HF, I think, and I opened up the slot with a grinder until it would slide ofer the sensor. I replaced the sensor without dropping the exhaust.

 

[crackie]

Thanks, Ed. That's really helpful. I didn't realize these sensors were so universal across cars.

 

[crackie]

Just closing the loop here in case useful to anyone else in the future.

So I had read elsewhere on the BB that this job was possible with "regular hand tools". While that may be possible, it wasn't obvious to me how one does that. You might be able cut off the top of the O2 sensor and then get an offset 22mm (or 7/8) box-end wrench over it. But then that wrench would also have to be unusually short to clear the exhaust down pipe (neither of my 2 offsets would fit…both too long). But even if you did it this way, you'd still have no way to tighten the newly installed O2 sensor (which doesn't have the top cut off). I know this because I tried it thinking I could just hand-tighten the new one enough (not in a exhaust pipe you can't). And, btw, you can cut (then break off) the sensor top with a hacksaw if you ever need to. (Obviously even easier with a die grinder. ;-) I also tried to remove with: 1) some long-nose vise grips; 2) squaring the housing of the sensor to get a wrench on it…housing is too flexible to twist like a nut.

At any rate, as noted in the post above, just get an O2 sensor socket (7/8 or 22mm) and cut a large enough notch in it to get it around the O2 sensor. Make sure you have a short enough sliding t-bar (AKA mini-breaker bar) to fit up in there. Larger breaker bar won't fit and neither will many (3/8-dr) ratchets. Soak the old O2 sensor the night before with PB Blaster and it'll probably come out "like butter".

Here are a couple of pics of the cut O2 sensor and the removal tool: