06 Bank 2 sensor 2 harness plug

Brewer00psd

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Good afternoon. First off thanks for having me on the forum.
I recently purchased an 06 manual 4.0l. I have a check engine light the previous owner said was due to a gutted cat. I was under it today and bank 2 sensor 2 plug is hanging on the frame and not plugged in. This is my first TJ and I am trying to figure out where the harness plug is and from where it should be coming from. Did some research and saw autos have it coming from behind the head across the top of the bell housing. Looked there and found on the passenger side a pigtail harness coming out of the main harness that runs to the coil packs. This pigtail has 4 wires with spade terminals but no plug on it and the wire color is not discernible. For what it's worth I attached a pic of the wires that are exposed with spade terminals attached.
Is this where the pigtail should be coming from and then running back behind the head to the driver side?

Thanks in advance for any info.
Matt

20260515_195953.webp


20260515_195602.webp
 
It does come off the main branch on the passenger side and go over and down on the driver side. I never understood that. Look at the top of the transmission bellhousing and perhaps it will be there. Obviously someone has been naughty. That could be it.
 
Thanks for the response. I'm going to peel back the harness covering try to verify wire colors and see if I can verify like that. At some point an owner did not do this harness any favors for sure.
 
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Thanks for the response. I'm going to peel back the harness covering try to verify wire colors and see if I can verify like that. At some point an owner did not do this harness any favors for sure.

It's very likely the right one. 🤞🏻
 
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Fysa the factory service manuals are available in the resources section and have full wiring diagrams in section 8w.

Rock Auto has the connectors under electrical connectors.

-Mac
 
Fysa the factory service manuals are available in the resources section and have full wiring diagrams in section 8w.

Rock Auto has the connectors under electrical connectors.

-Mac

Thanks for the heads up on the connectors and manuals. It will be a huge help.
 
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Good afternoon. First off thanks for having me on the forum.
I recently purchased an 06 manual 4.0l. I have a check engine light the previous owner said was due to a gutted cat. I was under it today and bank 2 sensor 2 plug is hanging on the frame and not plugged in. This is my first TJ and I am trying to figure out where the harness plug is and from where it should be coming from. Did some research and saw autos have it coming from behind the head across the top of the bell housing. Looked there and found on the passenger side a pigtail harness coming out of the main harness that runs to the coil packs. This pigtail has 4 wires with spade terminals but no plug on it and the wire color is not discernible. For what it's worth I attached a pic of the wires that are exposed with spade terminals attached.
Is this where the pigtail should be coming from and then running back behind the head to the driver side?

Thanks in advance for any info.
Matt

View attachment 688808

View attachment 688809

The wire insulation colors in your photos look similar the what I saw on my B2S2 harness-side connector. My connector was trapped between the transmission and body with all the copper wires exposed.

Screenshot 2026-05-15 at 18.01.04.png


I used a wire diagram from the FSM to trace the wires you see further up the harness near the back of the head until I saw the insulation colors I was looking for, and then labeled and spliced in extensions that were routed to the driver side. If that doesn't work, you could also run continuity checks from other areas like the ECM connectors using your FSM's diagram for guidance (I personally don’t like messing with those connectors unless I have to).

This diagram was sitting next to my connector photo in my phone from when I did the job a few years ago. I assume this is what I used for my 2005, but I'd double check your FSM to ensure it's accurate.

IMG_3073.jpg


It would be great if you could find a stock connector if yours isn’t around anymore or in working condition.

You could try to order one on RockAuto and hope it will key correctly with your B2S2 connector, or maybe ask in the forum if anyone has access to a spare harness connector or can find one online or at a wrecking yard (if you can’t find it yourself).

You could also switch over to something like a 4-pin Deutsch connector, but then you’d need to splice in the sensor side anytime you make a change. You also wouldn’t know if you received the wrong bank/sensor o2 unless you hold on to your current sensor-side B2S2 connector (assuming it’s correct)…and I also don’t know if it would matter since the connector keying may or may not be the only difference between a B2S1 vs B2S2. This isn’t meant to confuse or cause a debate, just things to consider so you don’t cause problems for yourself later.

Below is what I currently see offered on RockAuto. I wish their offerings were more promising and the prices were more reasonable. Sorry this isn’t more helpful.

Screenshot 2026-05-15 at 18.26.37.png


Ultimately, I’d try to get your hands on a working condition stock harness-side B2S2 connector if you can, and then splice in extra length so you can route it to the driver side. Best of luck man.
 
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