Thread: Black soot coming from exhaust of D2 V8

Went for a trip to the Erica pub and back. Noticed on Nanocom that the O2 bank B was varying from 0.00 to 0.70, O2 bank A sitting on 0.00 with no variation at all. I expect this means that the passenger side O2 sensor is u/s.

does it only run rich when warm?

o2 sensors are not used when cold/open loop.

Not sure why the stain now,, nothing has changed, and as eevo said when cold the O2's are ignored,,

no MAF faults?

Originally Posted by biggin

Went for a trip to the Erica pub and back. Noticed on Nanocom that the O2 bank B was varying from 0.00 to 0.70, O2 bank A sitting on 0.00 with no variation at all. I expect this means that the passenger side O2 sensor is u/s.

And that would be correct 0 and no change = dead

I had the same issue with my neighbour`s D2 ,
Straight to Pickapart in D/Nong 7 dollars for second handy fixed.

Have heared D2 o2`s can be pricey new
Oh make sure that the sensor is plugged in securely as if someone has replaced it some point they could have not fitted the new one correctly
Dont ask how i found that out

Now it's had a run, try it again from cold. Might be a leftover from before you did the work.

It is possible this problem has been around for quite a while. The man who refurbished the heads reckoned it had been running rich.
I've had no MAF faults, but I'm not sure what the Nanocom should read for a good one.
I also noticed Nanocom showing occasional misfire, but only on cylinders 3, 5 and 7, the same side as the faulty O2 sensor.
I think I will swap the sensors and see what happens.

TGO has maf values,,

On a cold morning the water vapour produced by the engine can condense in the exhaust pipe , mix with the carbon in there and drip onto the ground.

This causes the black stain, and similarly the water vapour trail from cold when you first go down the street.

There may be something wrong or it may be just the above.

FYI once the o2 sensors start to work, the MAF values are disregarded by the ECU until about 50% or more of throttle (closed loop) and the o2 sensors control the mixture. So if the o2 sensors are more than say 100KK old then they may be slow or faulty.
Regards Philip A