O2 Sensor From Hell... Post your war story and solution HERE.

[Navigator]

The upstream passenger side O2 sensor is a PITA. The others were replaceable, but that one appears to be impossible to get to. The connection is totally out of sight AND there is NO clearance to turn a wrench or splice wires. Who among us has tackled that SOB and won? Post your story and solutions here. Thanks.

[Navigator]

C'mon, no one here has changed all 4 oxygen sensors on their VX? Amazing...

[Vehi-Cross-Az]

I may be looking into changing a few of mine this or
next week...
crawled under mine today, located them all..
if you have the correct tools, its not as bad as it looks
really. They make special O2 sensor wrenches and sockets
for harder then most sensors to get to.
Matco and Snapon both offer their share of "specialty
tools" .
The one on the pass side you can get to the plug from
the top, its not that bad, just follow the wire up and youll
find it.
A crows foot may work too on getting them loose too
just be sure not to round off that sides, that happens alot
if they are stuck in there from age.

[Navigator]

Keep me posted of your progress.

I did deploy tools you suggested in my attempt, however in spite of having the proper tools the cleareance was to small to operate the offset O2 wrench in the space provided on the VX for the passenger side front sensor. I am sure there is a way to do it without removing the passenger side cat, but can see no other sollution at the moment.

I gained 3-5 MPG by changing out 3 oxygen sensors. With todays gas prices it is a worthy project. It also eliminated the occasional hesitation issue as well.

[crager34]

O2 sensors around $75 dollars each. Are there some cheaper somewhere?

[snowtrooper1966]

I found them on a site for around 35, but my home PC is down and that's where the link is...
I need to swap my rear 02's out, so I will be making this a priority soon. I will keep you all posted.
Best,

[catskilljay]

so i guess dropping the pipe is still only way at that passenger side front huh? n what about unplugging it.... grrr

[IndianaVX]

I don't recall exactly how I did it, but I did it without taking any pipes loose! I think I used a combination of the 02 socket, and an open end wrench. You can only turn it very small amounts at a time, but each bit is progress. The one " trick" I did employ..... I used a battery hold down bolt ( a long rod with threads on on end, and a bend on the other) to plug the sensor back in. Unplugging isn't a big deal, but plugging it back in, I took said rod, and hooked it over the top of the upper part of the plug and pulled slightly as I pushed the bottom portion of the plug up into it. You have to be careful not to tear up the insulation on the wires, but it worked like a charm. Just take your time and think it thru. It does take time, and your forearm will cramp a bit from the odd angle your arm will be in for the time it takes.
I'm assuming you had the cats checked to see if they were plugged up?

[EVO]

A piece of sheetmetal (heatshield) Visegrips and a propane torch is your friend!! Heat that baby up without burning anything and that puppy twist out like butter!

[catskilljay]

Well I am back drivable again. I changed the down stream O2 sensors. Rented the sockets from AutoZone and yes the torch helped. Also changed the fuel pressure regulator the same day So the combination of the two? Or one or the other got me going? Brought the car/truck to Monro muffler (a muffler brake chain on the East Coast) to have the cats tested. Or at least I thought…? They said they never hard of such a test... ie Testing pressure… Drilling holes, or going through the O2 entry? I think they banged on it and said it don't sound clogged. But that they could change the upstream sensors for $175 said they would drop the drivetrain to get at them better or something. So as of now she seems to run fine again unless I'm going up Steephill or really romp on it. The CEL blinks then stays on and I throw the p0300 code (multi-misfire). I did change all of the plugs, so next up I'll be checking the fuel injectors, coil packs and intake manifold gasket for leaks etc.

[IndianaVX]

Need to go to a different muffler shop....they are clueless, and shouldn't be in business!
Also, if they are telling you they need to remove the drivetrain to replace the 02 sensors, I will give you the translation....."WE ARE RIPPING YOU OFF"

don't give up on the clogged cats..... you could possibly blow a head gasket...that pressure has to escape somewhere.

[LittleBeast]

I replaced all 4 of mine with hand tools and the rented O2 tool from Pepboys in under an hour. Tough to break loose, PB Blaster is a necessity.

[catskilljay]

Thanks for your help Indy! and yes definitely going to get a few other opinions/quotes. And "littlebeast" is right lol.. it took me several hours just to remove my 2 downstreams with correct tools and torch but I could not even see where the passenger upstream plug/harness go's/is. let alone unplugging it? The driver side seemed like I could probably do it with a bunch of cursing and ingenuity. Hey LB Just wondering how you did your 2 front/upstreams so quick? I was wondering if we could go through the console under the shifters somehow to get to those plugs?

[quikride86]

I replaced 3 of the 4 sensors. As others have said the passenger side upstream sensor has a connector that seems impossible to get to without loosening the engine mounts and lifting it slightly. One tip I can share for the others is that both the downstream O2s would not come loose with a sensor tool. They just kept skipping over the hex 'corners' trying to round it off. I finally had to resort to using the air impact gun to persuade them loose. The key is use a sharp straight chisel bit and make an indent about an 1/8" before one of the hex 'corners' straight on, then angle the tool so that it's force causes the sensor to rotate in the loosening direction. If you don't have an air tool a cold chisel and hammer will work, just takes longer. Steve

[cudabuyer]

I removed the passenger front o2 sensor from hell EASY!