Luck ran out today, it started with rough idle and p0130 which is bank1 sensor1. I thought maybe I got some water in there from cleaning some parts of the engine bay (simple green and a spray bottle of water). I started with the connector and noticed that it was full and oil but also had some corrosion on both plug sides. Cleaned it up with electric contact cleaner and scrapped the plug side with a small dental pick. I noticed that on the engine harness plug side one of the spades in the connector is very loose and looks like it’s almost corroded through.

soooooo it’s basically impossible to reach that part of the harness without taking a good part of the top end apart. Anyone have any good suggestions to repair this? I have a spare connector from the parts car I stripped.

Just to see I straighten the spade connector and plugging in the o2 sensor and started it up. I get multiple misfire codes and blinking check engine which isn’t good.

pending codes p0135 p0300 p0307 p0130

 

I'm have a similar issue myself right now. During my HG replacement project, I noticed my DS connector was missing a chunk and full of oil. I splice in a spare. Now I have No voltage codes on both sides and I never touched the PS side. I thought my original splice might be bad and went back and redid it. Still no joy.
You can get to the harness, If you have SAI it is a PITA because the pipes are in the way. I removed the SAI pipes, the intake manifold and was able to get to the back of the valve cover. There is a bolt that holds the harness assembly in place. Small hands and patience and you can get it out. The other thing is the grounding strap ( or straps) bolted to firewall. remove nut so you can maneuver the harness.
A MAJOR WORD OF CAUTION: Be very careful as to your splices and how much wire you cut out. The wires are very brittle from age and heat. You will also find that once you pull off the wire loom that two of the wires are actually inside their own sleeve. In the sleeve are a total of three wires and the wire also has shielding. the third wire literally goes nowhere. I think some call it a draining ground. If you have to go back in to the harness to splice you may find that you do not have a long enough wire to connect to the oxygen sensor. This is true with Bosch sensor, but Walker sensors have a longer wire setup. I had brand new Bosch sensor so I had to buy an extension:
I would like to tell you the extension solved my problem but at this point I cannot. I'm having to take my D2 to an independent LR specialist to sort it out.

 

Thank you for the reply. I do have SAI which I figured would add to the fun. Truck was running perfectly until yesterday which is a bummer. I found the drain wire in the loom this morning on my harness attached to the spare transmission I have. I cut the spare harness way back so I have about 9” of wire to work with. I understand the area involved to complete this but just might bring it to a specialist to keep the colorful language to a minimum.

 

If you go down the specialist route keep us posted. I have already conceded defeat as my buddy who is a good wrench turner and I cannot figure it out. I am hoping to get my car into my guy this weekend.

 

Will do, I am in MA and close to Jwhite which is a great but pricey Land Rover specialist. This is a project truck for me but I know my limits and don’t want to make this problem worse.

 

I had this problem as well I just cut off the plug and took note where the wires go on the plug if I remember correctly the rear o2 sensor plugs right into the front o2 sensors.

 

Just to update, I have a garage within 1/2 mile of my house that I trust. I brought the spare connector with wire I had and dropped it off. They said it was a pain but where able to fish out the harness and splice in the used connector and so far so good for a couple days but only driven 10 miles so far. $300 in labor.

 

I ordered some dielectric grease today to put on these connectors as a preventative maintenance

 

I thought dialectic grease was a no no for Bosch O2 sensors since it pulls reference air down the wire to the sensor?

 

Now that's something I've never heard of, wires carrying air.. Or did I misunderstand?