Ye Ol' Cherokee

I just ordered 2 NGK o2 sensors to replace mine. The downstream is bad, so i figured i would just replace both.

Any particular way to replace them?

Any tips or guidance will be helpful and much appreciated

Stabsthedrama

Soak the crap out of them with pb blaster, ideally for a day or so before doing it.

The "o2 sensor sockets" are nice if you're trying to preserve the o2 sensor wire, but honestly the best way to do it is go in with both feet and snip the wire, and get a wrench on it.

Heat is also a good tool if they want to be stubborn. Heat the crap out of the tube (not the sensor) - I mean cherry red hot, and use some pb blaster in between doing so, it will seep in a bit but most will burn off (only go this far if it's being a real pain)

The downstream ones are usually easier from my experience, especially since they're easier to get a good long wrench/breaker bar on if needed.

I had an upstream one on a 96 that I swear on anything was cross threaded from factory (which I have heard does happen). I had the entire pipe off and no matter WHAT I did, it wasn't budging, wound up just replacing the pipe.

You should be fine though, it isn't too bad.

For the upstream one on my renix though, dflintstone had a good tip - jacking up the unibody and letting the axle stay down and go at it from the front - gave me a lot more room. The 96 I didn't really remember this being a problem with, but the damn thing wouldn't come out anyway.

Roler

Got my two sensors still here in their box....can't get the old ones out, had a shop have a go at it too and they stopped trying because the whole cat began to twist with the attempt...So, I'll be reading along here....

Stabsthedrama

Like I said, I would swear on ANYTHING they get cross threaded, somewhat commonly, from factory. I wanted to throw a party when I did the one on my renix the other day and it didn't give me any lip.

With this in mind, I'd be cautious to advise anyone snipping the wire before knowing they can break it free first. Just a thought.

extrashaky

I agree on soaking it in PB Blaster. You can use a pencil torch to heat the bung if you still have trouble breaking it loose. Harbor Freight has them fairly cheap.

When you put the new ones in, make sure you use anti-seize compound on the threads to help avoid stuck sensors in the future. The sensors may come pre-lubed or with a little tube of anti-seize in the box. One of mine had a tube, the other didn't, but the one that did had enough for both. If neither of yours had anti-seize with it, get some.

Disconnect the quick release connectors before you try to remove the sensors. If you try to unscrew it with it still connected, you'll twist the wires and may risk damaging the wires on the truck side of the connector.

The front connector should be easy to find. The rear connector may be tucked up above a little mounting shield welded up in the drive shaft tunnel. It has a plastic pin that holds it in a hole in that shield, but it just pulls out.

I think those O2 sockets are pretty much worthless because they move the wrench handle up higher, closer to the body, where you don't have as much clearance to work. There's no way I would even be able to get the socket on my rear sensor without dropping the cat. I actually bought one of those sockets with my Rock Auto order and ended up not using it.

I prefer a long open-ended 7/8" wrench. If the open-ended wrench wants to slip off, you can snip the wires and put the box-end over it for a little more secure fit. If that fails, and you have a good quality wrench that won't bend, you can slip a piece of pipe or box channel over the wrench to give yourself more leverage.

Mine actually came out pretty easy, so it's not always a hassle. Good luck!

Kalali

You obviously did not heat the "crap" or soak the "crap" or even beat the "crap" out of it.... Crap is operating word here... Go back and try again.

Stabsthedrama

By the way they do have a socket for o2's as well as a wrench with a slit in it to slide the wire through.

I agree they're not really worth it though. I have the socket and got off the upstream ones off rather well with it without having to snip the wire. (didn't want to risk having a stuck o2 sensor after cutting it) - it gave me good peace of mind.

Roler

Tried all those,mate. Of course. Except the beating.
After all, those are all the 'known' tricks...

peelman

I removed the front o2 using a small pipe wrench and 3 ft piece of pipe, quick snap to the right and out she came. If there's nothing wrong (codes) with the o2 just leave it be.

Roler

To the right?

And no, O2 sensors do not have an indefinite lifespan. 100-150K.
They will need replacement at some point.

sycoglitch

O2s are so easy to place. Have done my uppers about 3 years ago and finally did the lowers recently, when I did the lowers I replaced all 4. Drive for 30mins. Get the pipes nice and hot. Use an open wrench. Then you can slowly massage it open. That's all there is. Th lowers I was on my back on the floor. The uppers you can get from above or below

DFlintstone

Probably a typo, (one I could make), but reminded me. Now and then something will crack loose clockwise, that seemed seized. Something to try if nothing else is working. And heck Roler, that might straighten out your stuff!

Firestorm500

Actually, to loosen them, you are moving the wrench in an arc from the left to the right.

Roler

it might be my sleep deprivation by now, but...isn't left to right...fastening them?
Let's make this more clear: clockwise or counter clockwise to loosen?

DieselD

x2 drive a while on highway, then come home and do it. (I guess you might be able to just sit there on the throttle for 15 mins but that's no fun.

I ended up using a big (1-1/2" I think) adjustable wrench. A little torque on it and it came right out. Well upstream anyhow. Downstream I was replacing more of the exhaust so I didn't have an issue there. Probably would've been seized if I had tried it.

I put copper anti seize on the thread when I reinstalled. There was some kind of anti seize on there from NGK but I figured more can't hurt.