O2 milivolt scaling verses true afr

[Turbotdr]

Where is a scale for translating the o2 millivolt to AFR readings , I was wondering what the readings do in scale .

 

[EricM]

Unfortunately there is no such scale. All we can say is if the stock narrowband O2's are up around 780-800mv, it's "most likely" richer than 12.0 A/F. We can't really derive any more info than that.