Missing 02 sensor plugs

[Steve Allen]

Bought a 2000 project. 4.0 auto. Lots of stuff wrong, but making progress. Where I’m stuck currently are where the 02 sensors plug into the wiring harness. This Jeep does not have the mini-cats, just the main cat under the skid plate. There is a o2 sensor on exhaust pipe closest to the firewall that is not plugged in and I can’t find any connector on the harness. The other exhaust pipe closest to the front of the engine has a place for a sensor, but has a plug in it instead of a sensor. Even if it had a sensor, again I see no where to plug it in to the harness. I also have an 06, but comparing the 2 doesn’t help. Too different. This Jeep has been messed with a lot,but as far as I can tell it is the original engine and harness. The PO told me that he replaced the cat a few years back and had the guy replace the 02 sensors. There is another o2 sensor in the pipe after the Y and it is connected on the passenger side of engine. In the pic you can see one pipe has the sensor, which is not plugged into anything, the other has the plug. I don’t even know how many this thing is supposed to have.
Sorry for the overabundance of info, but trying to give adequate detail.
Any help appreciated.

 

[flyinfish]

Here's a link to grab the Service Manual for your Jeep. The 2000 manual is in the second to last row on the right.

https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/

 

[TheBoogieman]

97-99 and some early 00' models didn't have the mini cats. Two 02 sensors.

 

[flyinfish]

 

[flyinfish]

Here's the 99 year

 

[Steve Allen]

OK now were getting somewhere. My 00 produced in 02/2000 should have two o2 sensors, based on the fact that there are no pre-cats. One before the cat, which is there, and one after the cat, which is not there. Not even a place on the pipe between the cat and the muffler to screw one in. If I had an exhaust shop add the bung, where would I plug it in? I don’t see an unused connector anywhere.

 

[Steve Allen]

Found it!!!. Wow it’s really hard to see because of the skid plate, but the downstream sensor is at the very end of the cat on top, and it is plugged in. So what started all this is the exhaust guy installed a sensor in the bung up at the manifold and with nothing to plug it into its just hanging there. When I bought the Jeep I am of course trying to find where to plug it in. UgggHH!

Thanks for all the help guys. Sometimes you just gotta keep digging until something clicks!!