P0131 O2 sensor circuit low voltage, bank 1 sensor 1
- System
- Powertrain - engine and transmission
What P0131 means
"O2 sensor circuit low voltage, bank 1 sensor 1" names one sensor precisely and one measurement: the voltage from the first oxygen sensor on bank 1, the one ahead of the catalytic converter, sat below the range that circuit is allowed to report. Bank 1 sensor 1 is the engine computer's own numbering. The code records the voltage and where it was measured, not what the mixture was doing.
This is a standard code. It means the same thing on every make of vehicle.
What the program shows for P0131
The Dashboard carries O2 sensor (rear), O2 sensor current, O2 short trim B1 and O2 long trim B1, and the Full scan's on-board self-tests list the oxygen sensor results bank by bank and sensor by sensor with the limits the car judged them against. The Inspection screen says whether the oxygen sensors monitor has finished.
The Dashboard shows Short fuel trim and Long fuel trim, Air flow, Manifold pressure, Intake air temp, Coolant temp, Throttle position, Accelerator pedal, Air/fuel ratio, O2 sensor (rear), O2 sensor current and whether the Fuel system is in closed loop. Record a drive and the Analysis screen gives the total correction At idle, Fuel trim against air flow, and whether the air flow and pressure sensors agree; the Full scan's On-board self-tests list the Oxygen sensor results by bank and sensor. Record before and after a repair and Compare shows the change in short, long and total trim at idle plus which codes are Gone, New or Still there.
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