pcmhacking.net

Can an accurate(ish) estimation of a/f ratio be interpreted from n/b o2 voltage, or as per nb a/f display, is erroneous/on-off.
Is then a conversion table available for volt to a/f?
Sorry in advance if i missed one in my searches, couldn't find much.
would 900mv @wot generally be lean or rich?
Thanks people.

It can give an accurate indication of which side of stoich your on. But for an actual AFR its highly inaccurate as the voltage vs AFR of non stoich changes with temp and exhaust back pressure. This is roughtly what the sensor output looks like ..


900mV most would consider pretty rich, but to tell how rich needs a wideband. The AF display your looking at in TP is the target AFR, what the PCM thinks the AFR should be based on the airflow entering the engine. You want that to be the same as the actual value measured by a wideband.