Thread: P38 Owners - Oxygen Sensors???

Originally Posted by cyclone

Did we get Oxygen sensor fitted to our vehicles from factory?

O2 sensors were not fitted for the Australian market.
They came into the country as a commercial vehicle (or similar) & didn't have to comply with all the regulations as such.

Originally Posted by Scouse

O2 sensors were not fitted for the Australian market.
They came into the country as a commercial vehicle (or similar) & didn't have to comply with all the regulations as such.

Wha???? I certainly have things that look like O2 sensors plugged into the exhaust on both banks before the CCs. Have I misread your post Scouse?

Originally Posted by glenhendry

Wha???? I certainly have things that look like O2 sensors plugged into the exhaust on both banks before the CCs. Have I misread your post Scouse?

Early GEMS P38's in Aust didn't have sensors. Later GEMS engines and all THOR engines have sensors. I don't know the exact date of the changeover, maybe there isn't an exact date, Land Rover style.

The late GEMs sensors are 5V lean, 0V rich, where the THOR are standard 0V lean, 1 volt rich sensors. Not compatible.

My March 97 build has them. So before that date. I also note that the vapour pipe from the charcoal canister goes into the throttle body on mine and in pics of 95 models this goes into the plenum. Maybe when this changed it is an easier identifier?

I think they were first fitted in 96. They then changed type with 97MY which continued until THOR type in 99. There were definately a few different types. Junosi on here did the research and I think the result was that there was no benefit in terms of economy. Also the early gems ecu wasn't capable of accepting them, due to the type of Fuel Map used.

the 95spec non o2 sensor cars can have the co% checked and reset (should be done very 40000km) especially if they have had the adaptions reset as this makes them run rich right through the range. on Testbook it is called an open loop tune.

I wonder if the "Open Loop" Tune is part of the Fault Mate Package as well?

Originally Posted by BusinessConnected

I wonder if the "Open Loop" Tune is part of the Fault Mate Package as well?

You can change the AMFR setting (air flow) and the other adaptive air setting - neither of which 'adaptively' change on non O2 cars unless manually set (according to Faultmate literature). I believe the air settings are what is 'tuned' on non O2 sensor cars. I understand that its meant to be done with a probe inserted into the exhaust for correct calibration. Cars with O2 sensors calibrate themselves - in theory. From what I could gleen at the time I last looked O2's were really only fitted for emissions reasons and that a properly tuned non O2 sensor car could run at least as well. The engineer I spoke to at Melbourne Land Rover last year seemed to think I was crazy for wanting to retro fit them into my vehicle, as he was insistant that the non O2 ones run better /shrug. I had to have them for my Tornado chipset to function so have them fitted now - Tornado doesn't work well without them...

Also, as Stubee noted, early P38 ECUs won't recognise them. You'll probably have the wiring loom etc all there (mine did) but installing O2's won't help unless you change the engine ECU (as I have). Unless you're planning on putting a performance chipset in I'd say there's no real advantage to having O2's, aside from emissions.