RR/Disco : Emission Control : O2 Sensor

O2 sensor

(about 1 hour to replace)

I replaced my sensor with an Nissan aftermarket part. The O2 sensor is a three wire unit. Mine cost roughly $70 then another few dollars for the butt connectors used to splice the rover plug with the Nissan sensor.

The rover sensor is across the top with the longer lead. The Nissan sensor is the one with a shorter cable.

The Nissan wires are the ones which have the zip-tie on the black insulation.
     

The completed cable. I covered the connectors with a section of plastic tubing and then wrapped it with some aluminium tape as shielding.
 

When you reinstall the sensor BE SURE to tie the wires back so they CANNOT CONTACT the exhaust pipe. Unfortunately I did not.

In the fall of 2000 Sheri and I were on our way up to Boston. We came to a sudden stop because of three lanes of gridlock. As soon as we stopped smoke poured out from the dash and under the passenger seat. Not good! We managed to push out way to the breakdown lane. By the time we stopped the smoke was disappearing and no more was coming. It smelled like and electrical fire but I wasn't sure.
I looked all over the vehicle and didn't find anything wrong and it ran fine. So we continued on our trip. It wasn't until February when I had the alternator rebuilt that I found the O2 wire. It had burned the insulation off of the white-orange wire from the sensor all the way back to the fuel pump relay. The wires had melted all together. I'm still in the diagnosis process but things are finally looking up.

Nissan part information
Here is an excerpt taken from the land-rover.team.net mailing list:
"
FROM: Richard Atkinson

NTK Technical Ceramics make only one 3-wire heated M12 x 1.25 titania-type sensor. The part numbers for the specific applications have differences only in wire colors, wire lengths, and the connectors. This means that the Rover, Nissan and aftermarket parts are functionally identical.

Currently there is a Federal requirement for OBD-II that sensors must be able to last at least 100k miles, which left NTK, Siemens, Bosch and Nippondenso making M14 and M18 parts. However, I understand that AC Rochester (Delphi) are due to re-enter the fray soon. In the M12 size, NTK and Siemens are the only makers, although I've yet to hear of a Siemens sensor (reboxed for Bosch Aftermarket in the US) actually being supplied.

My own Rover experiences, however, are limited to suggesting the purchase of, and then assisting, a colleague re-connector his pair of Nissan 22690-88G01 parts, which work perfectly. (As I recall, I think their final cost was around US$52 each). My own vehicle has 88k miles on it now, so the EGOs will be due for changing soon. I will be applying the ultimate criterion for my selection - the parts with the lowest price!
"