So much for a "low profile" creeper haha

 

A 7/8" box wrench is the best tool for O2 sensor removal. A 22mm is also a good fit as they are essentially the exact same size (down to a few decimal points).
Unplug it and the box end slips over the connector (or cut it off the sensor side if it has the earlier GM weather pack connector). Can't remember off the top of my head which the 95 will have. I currently have an 88 MJ and an 00 XJ. And did all O2 sensors in the last year.
The open end is fine for replacement, just past snug is all you need just like a sparkplug. All the replacement sensors I have purchased in the last few years have had anti-seize preapplied out of the box.

The rear 02 sensor has no effect on engine function if you have it, only the manifold sensor effects engine function. The rear most merely confirms catalytic converter function. And as stated is an OBD II thing anyway.
Bosche sensors are OK, but do not function as smoothly as the NTK's do. I have a Bosche up front and an NTK in the rear of my 2000 (rear is actually on an elbow to simulate a cat).
Only noticed a bit of extra vapor at start up after sitting a few day in winter with the Bosche. Will eventually swap to NTK eventually.

 

That's good news at least. I wonder why Rock Auto lists a downstream sensor.

Not likely. PB Blaster can flame up if you spray it on hot exhaust parts. But if it's cool when you spray it, by the time you heat it up again most of the flammable part will have evaporated away.

Since you're waiting for parts to arrive anyway, I think I would go ahead and hit it with the PB Blaster today and let it soak. It takes time for that stuff to work.

I just bought two sensors for my 2000 (front and rear) when both were fouled after my engine installation, probably by the ceramic coating on my header. The Denso front sensor had a little tube of anti-seize in the box. The Ultra-Power rear sensor didn't have any anti-seize at all, no tube, nothing on the threads. Fortunately there was enough in the tube to do at least five sensors, so I had enough for both.

Coffeechick, the NTK should have anti-seize with it. But **** happens, and if it's missing go get some at the local parts store. You don't really want to skip that step.

 

Yeah. If I don't have the right stuff already, I'll grab a tube from the store when I get another can of PB and a can of BraKleen. Used up the last can carefully cleaning the drive belt compartment on our ZBoards.

I have two days left to wait until it shows up, so that's plenty of time to pre-treat and pre-treat again.

And thanks for the sizes. I'm terrible at judging where to start testing with wrenches or sockets, for some reason. I keep hoping I'll get better, but nope.

 

Hunter,

Glad to see you're still in the hunt and your Heep is still kicking; albeit with a presumed bad O2S.

Have you inspected the wiring from the O2S up, and into, the engine bay for chafing or other such damage?

 

OBD I Code 21= OBD II Code P0132.

From 2001 Diagnostics Manual:

P0132-1/1 O2 SENSOR SHORTED TO VOLTAGE

When Monitored: With battery voltage greater than 10.4 volts, engine running for more than 4 minutes and coolant temperature above 180°F.

Set Condition: The oxygen sensor voltage is above 1.5 volts.

Possible Causes:

O2 SENSOR OPERATION
O2 SENSOR SIGNAL SHORTED TO VOLTAGE
O2 SENSOR SIGNAL CIRCUIT SHORTED TO O2 HEATER OUTPUT CIRCUIT
O2 SENSOR SIGNAL OPEN
O2 SENSOR GROUND CIRCUIT OPEN
PCM

Have you inspected the wiring from the O2S up, and into, the engine bay for chafing or other such damage?

 

I'll give it another good looking-at when I go out to spray the part down with PB again later tonight. And probably a really, really close examination again when I go to switch out the part, which is probably advisable anyway, because I'm pretty sure it's the same sensor the Jeep got issued when it was built.

The new part came pre-coated with what I'll assume is the proper stuff on the threads, so that's one less thing I have to buy.

If I do find a problem with the wiring, what would I do to fix it?

And of course I'm still doing this. After all the work I already put in [and the work I have left to do], I'm not going to give up unless something terrible happens to the engine or the transmission.

 

So, there I was, box in hand, thinking 'why not just go take care of this now?'

Colorado weather responded with a sense of confusion--wait, it's 13:00, why is it night? Then, thunder. Wind. Rain. Hail.

Dead bird.

Tomorrow, then.

 

Done.

It was a hell of a fight. I had to call in reinforcements. Male reinforcements. But it surrendered in the end.

Put the new one on, poked around at a few other things, then went off for a test drive.

Short hop first. I knew that the light would come on by the time we got to the intersection.

No light.

Taking a longer drive now. Just to be sure.

On to the next problem.