Left Upstream O2 Sensor Removal


cmcolfax

Forum Member

EMT / Paramedic
Firefighter
GMRS Radio License
Joined
Sep 19, 2025
Messages
168
Points
101
Age
55
City
Williamsburg
State - Country
VA - USA
Other
2007 Volkawagen MK5 Rabbit 2.5
Vehicle Year
2011
Vehicle
Ford Ranger
Drive
4WD
Engine
4.0 V6
Transmission
Manual
Total Lift
None yet ;-)
Tire Size
265/75/16
My credo
Facta Non Verba
Yes, I searched.

Yes, I have the crow foot o2 sensor wrenches/sockets.

Yes, I pulled the inner fender liner.

Yes, I soaked it with PB.

I got the other three done.

Yes, they were kind of a PITA.

But THIS one is šŸ¤¬šŸ¤¬šŸ¤¬šŸ–•šŸ–•šŸ–•

I can get the socket on it.

I can get a ratchet or a breaker bar in the socket.

But there is ZERO room to turn said ratchet or breaker bar.

Any ideas?
 
12-point wrench?

I’ve used one when it’s been necessary because of lack of room. It usually doesn’t fit on without trimming some plastic off the plug or un-pinning the plug, I’ve done both.

For the really stuck ones I’ll heat the bung on the exhaust cherry with a torch and then wrench like crazy. After it’s out and cool I’ll run a tap through (spark plug taps are the same thread) just to make sure there’s no bits stuck to mess things up on reassembly.

Currently I’m testing out a high temp copper anti-seize compound to see if that helps with keeping them from sticking.
 
It's already unplugged, IDGAF if I have to clip the wire.

Gonna give my new toy a shot now...
 

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I used hi-temp copper anti seize and ran a thread chaser thru on the other three. šŸ‘
 
It's already unplugged, IDGAF if I have to clip the wire.

Gonna give my new toy a shot now...
I should probably get one of those
 
What is this sensor that plugs into the side of the transmission?

It looks like it is held together by a c clip.

If I could get that wire out of the way I would have a little room.
 

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  • Left Upstream O2 Sensor Removal
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Vacuum line maybe? Vent line? Not really sure offhand. Hopefully someone else knows, I can’t really go poke at anything at the moment and try to figure out what it is.
 
This is my first time using it! šŸ¤·ā€ā™‚ļø
I’ve been using an oxy/acetylene or oxy/propane torch for the last like 20 years, but I’ve seen people use those induction heaters and I know that sometimes a torch either doesn’t really fit or there is lots of stuff that can be inadvertently melted nearby where you need to use it where that wouldn’t be as much of an issue with the induction heater
 
I should probably get one of those
This is my first time using it! šŸ¤·ā€ā™‚ļø

I've heard that they aren't necessarily all they're cracked up to be apart from some rather niche situations where using flame is an absolute no-go.

Let us know how hot she can get things cookin.


I've always wondered about the effectiveness of getting reeeeeeeally stubborn crap broke free by getting it ripping hot and then immideately hitting it with some 'bolt-freeze' or whatever it's called. Id imagine going from hot AF to cold AF within a second or two would help stuff crack itself loose rather well..
 
I've always wondered about the effectiveness of getting reeeeeeeally stubborn crap broke free by getting it ripping hot and then immideately hitting it with some 'bolt-freeze' or whatever it's called. Id imagine going from hot AF to cold AF within a second or two would help stuff crack itself loose rather well..
That does work too. I’ve tried it. One thing I do love about a torch is if heat and/or heat to cold doesn’t do the job, there’s a handy little magic lever on a torch that reduces metal to liquid. Can’t be tight if it’s a liquid.
 
I've heard that they aren't necessarily all they're cracked up to be apart from some rather niche situations where using flame is an absolute no-go.

Let us know how hot she can get things cookin.


I've always wondered about the effectiveness of getting reeeeeeeally stubborn crap broke free by getting it ripping hot and then immideately hitting it with some 'bolt-freeze' or whatever it's called. Id imagine going from hot AF to cold AF within a second or two would help stuff crack itself loose rather well..
The limitations showed themselves.

In theory the "coil" should go around the fastener that needs to be removed. The magnetic field is strongest inside the coil and that's what heats the metal.

Well, where the problem fastener is in this use case prevents me from getting the coil "around" it.

(See above photos... The crow foot socket is around the sensor in them... No way to get the coil around it.)

FWIW, that's the approach I was going to take. Red hot then squirt with cold water from my Blackstone griddle bottle! If I had thought to pick up a can of "Freeze-Off" I woulda used that...
 
Vacuum line maybe? Vent line? Not really sure offhand. Hopefully someone else knows, I can’t really go poke at anything at the moment and try to figure out what it is.
I'll look into it further later.

For now, the truck sits on one jack stand with its left front wheel in the air until Thursday...

12-hour shift at the Part-Time gig tomorrow and my regular 24 at the Firehouse on Wednesday...

Thursday was supposed to be oil change on the VW and lawn mowing day. 🤬
 
I'll look into it further later.

For now, the truck sits on one jack stand with its left front wheel in the air until Thursday...

12-hour shift at the Part-Time gig tomorrow and my regular 24 at the Firehouse on Wednesday...

Thursday was supposed to be oil change on the VW and lawn mowing day. 🤬
Sounds about right. Can’t tell you how many times that sort of thing has happened to me. Currently I’m surrounded by broken stuff that I can’t fix fast enough. Hopefully tomorrow I can finish fixing the brush hog so I can measure for a driveshaft and hopefully the next time we get a few dry days in a row and my property is less of a swamp I can mow it.
 
FACTS.

I spent all afternoon Saturday getting my lawn tractor to run again.

( I HATE chasing electrical gremlins. )

Worked my 24 yesterday.

Technically today was supposed to be lawn mowing day...

It also doesn't help that I have been out of my ADD medicine since Friday. šŸ‘€šŸ¤ÆšŸ‘€
 

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