Thread: oxy sensor dramas

try before,, the passenger one is easy to see,, cant say I've ever noticed one on the drivers side--

no markings on the pipes after the cats,,

The US ones had 4 but not ours from what I know. I just replaced mine Keith new ones and it's still throwing o2 codes . It hasn't got a clue!! Cheers

Originally Posted by ozscott

The US ones had 4 but not ours from what I know. I just replaced mine Keith new ones and it's still throwing o2 codes . It hasn't got a clue!! Cheers

All US spec LR's since the D1 1996 4 litre /P38 4.6 have post cat monitoring.

It seems your set up is akin to Euro/UK spec with down stream control only.

A couple of points, if your valve covers have been leaking and soaking the O2 sensor sockets it can carburize and corrupt the signal, hence no control. Also its all to easy to misplace the pins in the harness side of the sockets as you push the O2 side home, equally they sometimes do not connect properly with the same effect.

If the system is running weak, like you have a defective Maf sensor, intake pipe holed/perished or other plenum/manifold leak it won't switch either and throw a defective 02 code. Worth looking into!

What I do is pull a plug wire insert a spare spark plug and ground it down then start the engine. With a miss-fire on one bank the enrichment will cause the 02 on the effected side to react if a weak mixture fault is present.

I haven't studied a UK spec D2 for a while, but it may also be worth looking at the fuse box under the hood. There is a fused circuit for 02's on the NAS units and a relay. On one or two models I have found that over time the harness sockets partially fall out from under the fuse box. This kills some circuits including the 02's. Be mindfull if you have had a gassing battery. The fumes collect under the battery cover and propogate under the fuse box corroding the sockets on the underside; always worth a look.

Hope that is of some help
Dennis
zedecars