Wideband sensor in a miss situation, more theory.

[Jmoore124]

So I am curious. In a scenario where my motor was missing (say above 3k rpm, turbo application) on one cyl. would a wideband 02 read rich or lean? I thought rich at first because of the additional gas, but I guess you can only have a certain amount of evaporation saturation and I am not really sure if that would be able to overtake the additional 02 provided by the lack of combustion. Again, just a theoretical question.

[PapaSmurf2k3]

I believe the answer is lean. You might want to check with the manufacturer of the sensor though.

[Jmoore124]

Thats actually what I was told by someone. I tried doing some logistical math, but I do not understand theory that well.

[PapaSmurf2k3]

The theory is that the O2 sensor measures the remaining unbonded oxygen in the exhaust. Combustion bonds air O2 with fuel, making Co2, Nox, etc. When there is a misfire, none of that oxygen gets bonded with any of the fuel, so the sensor should read that there is a LOT of oxygen leftover after combustion.