PID 14V
O2 sensor B1S1 voltage
Front oxygen sensor voltage (bank 1, before the catalyst).
What is normal
On a warm engine it swings roughly between 0.1 and 0.9 V several times a second. Frozen near 0.45 V means the unit stopped listening to it.
These figures hold for most cars, but the maker has the last word: some engines run hotter or idle higher by design.
Codes about this parameter
P0130Upstream O2 sensor circuit malfunction (bank 1)P0131Upstream O2 sensor circuit low voltage (bank 1)P0132Upstream O2 sensor circuit high voltage (bank 1)P0133Upstream O2 sensor slow response (bank 1) — usually a worn sensorP0135O2 sensor heater circuit malfunction (bank 1, upstream)
We have a detailed piece on thisSecondary air: P0410, P0411, P0412 and the emissions test
Codes behind this reading
If the value is out of range, the unit usually says so with one of these codes.
P0130Upstream O2 sensor circuit malfunction (bank 1)P0131Upstream O2 sensor circuit low voltage (bank 1)P0132Upstream O2 sensor circuit high voltage (bank 1)
How it feels behind the wheel
The same fault shows itself in different ways. Each sign below says what to look at in the live data.
How to see it
In CarScan: the Live data tab, «Start polling». The app asks the car several times per second, draws a graph and remembers the highest and lowest value of the trip.