What Is This Plug? O2 Sensor Question

[radjxf]

Been working on the son's Rover, trying to eliminate ta plethora of codes. While installing all new O2 sensors, I see this plug on the right side of the transfer case not connected to anything:



Can't find anything that it connects to? Looks like it's wires run to the rear of the vehicle, but can't tell where. Not an easy place to see or feel around either. Oh, and the prior owner had the trans rebuilt last year---most of the wires have been ripped from their mountings and are just hanging loose.

Second question: replaced ALL FOUR O2 sensors with new Bosch sensors. Previously had fault codes for both upstream sensors. Now the Bank 1 upstream sensor reads ZERO! I made sure the connector was very clean and also sprayed full of quality electronic cleaner. Here's what the Ultragauge shows:



Any ideas welcome. Thanks

 

[n8thgr8]

Looks like an O2 sensor plug

 

[ubuntu]

That is the rear O2 sensor plug. It could be the right rear one, it looks like the left rear one is plugged in. Find the right rear O2 sensor on the Y pipe and then follow the wire, it will most probably be hanging loose.

 

[Tugela]

If you replaced all 4 oxygen sensors and one of the female plugs has nothing connected to it, then to what did you connect the male plug of the 4th oxygen sensor? Assuming you connected all 4 plugs to something.

 

[radjxf]

I connected the right rear O2 sensor to the correct plug. It won't even plug into the empty plug shown above. It's wires travel somewhere to the back of the Rover.

The error is coming from the left front O2 sensor. It is also plugged in correctly to a cleaned connection. I can't see where the wires go to trace them to rule out pinched wires, etc. Also covered in oil as this thing leaks like a sieve. Again, I did make sure the orange connectors were VERY clean and snapped together positively.

 

[SkiahTigr]

Were you getting 0 volts from that sensor before you changed them out?

 

[radjxf]

Were you getting 0 volts from that sensor before you changed them out?

I thought it was reading poorly, i.e. out of range, but cannot definitively recall. I may have to dig up an old one (if I haven't taken out the trash) and swap it in to verify. I recall that particular one is a bi**h to get to compared with the others.

 

[SkiahTigr]

I thought it was reading poorly, i.e. out of range, but cannot definitively recall. I may have to dig up an old one (if I haven't taken out the trash) and swap it in to verify. I recall that particular one is a bi**h to get to compared with the others.

Hate to make you do more work, but that's what I'd do. Make sure you swap the correct one in, if memory serves they're not interchangeable left to right on the front sensors. Swap it in, if you're still getting 0 volts, you've got damaged wiring. If I remember correctly, the during for the o2s goes into the harness that runs behind the engine, same one the Crank Position Sensor and coil pack goes into.

 

[radjxf]

Now BOTH fronts are measuring ZERO on the Ultragauge! WTF?
There are no right or left sensors, just fronts/rears on my Disco (I definitely go that part right).

Yesterday I had the following TC's:
P0171
P0174
P0130
P0150
Pending: P1174 and P1129

Now today I have:
P0130
P0174
Pending: P1174 and P1129

I had less problems before I replaced all 4 sensors to the tune of $280....:banghead:

 

[seventyfive]

that female connector is a 2 position connector...don't worry about it until you need to.

An oxygen sensor is a 4 position switch, so dont confuse the OP with incorrect information.

OP, verify you did not have pins push out on the new oxygen sensor connectors. If they are Bosch I wouldn't be surprised if one or several pins pushed out or they are just shit out of the box.

 

[radjxf]

that female connector is a 2 position connector...don't worry about it until you need to.

An oxygen sensor is a 4 position switch, so dont confuse the OP with incorrect information.

OP, verify you did not have pins push out on the new oxygen sensor connectors. If they are Bosch I wouldn't be surprised if one or several pins pushed out or they are just shit out of the box.

Thanks for the info. I thought Bosch were the preferred ones to get? I had to order these, as they don't keep shit locally other than universals. Hope I can get refunds if some of these are bad--not sure how you can return installed sensors? What brand is better than Bosch? Unfortunately, I cannot afford genuine sensors at $250@ right now....

 

[seventyfive]

I prefer NTK, which is made by NGK.

Before you start swapping parts just verify all the pins are intact on the harness and sensor sides. I've had pins push out and I've actually seen pins bent.

 

[radjxf]

Finally got a bit of time to work on this POS today. Unplugged BOTH front O2 sensors, cleaned the piss out of them with MAF cleaner, compressed air, applied dielectric grease and inspected for bad pins per seventyfives advice---all plugs looked good.
Now the bank 2 upstream sensors actually reads out, but very low mV, i.e. around 0-0.065.
Bank 1 upstream sensor still reads ZERO.
So, I picked up some new Walker sensors from a guy that bought them and never used them---purchased them solely as test mules. Swapped out ONLY the Bank 1 upstream sensor that formerly read ZERO. Now it reads very low mV as well. Here's the kicker, the Bank 2 sensor that I did not swap out, now is reading ZERO. Mother of God I hate this f'ing thing!! Payback for all the bad shit I did as a misspent youth!
I would throw in a MAF sensor for kicks, but this damn thing has just about drained my wallet.

 

[ranf5]

Finally got a bit of time to work on this POS today. Unplugged BOTH front O2 sensors, cleaned the piss out of them with MAF cleaner, compressed air, applied dielectric grease and inspected for bad pins per seventyfives advice---all plugs looked good.
Now the bank 2 upstream sensors actually reads out, but very low mV, i.e. around 0-0.065.
Bank 1 upstream sensor still reads ZERO.
So, I picked up some new Walker sensors from a guy that bought them and never used them---purchased them solely as test mules. Swapped out ONLY the Bank 1 upstream sensor that formerly read ZERO. Now it reads very low mV as well. Here's the kicker, the Bank 2 sensor that I did not swap out, now is reading ZERO. Mother of God I hate this f'ing thing!! Payback for all the bad shit I did as a misspent youth!
I would throw in a MAF sensor for kicks, but this damn thing has just about drained my wallet.

Reviving an old thread. Did you ever resolve this ? I'm running into a very similar issue.