Honda P0131-Primary HO2S Sensor 1 Circuit Low Voltage

Honda P0131 Primary Heated Oxygen Sensor (O2 Sensor) Circuit Low Voltage Sensor 1

Code P0131 Honda is DTC code for (O2 sensor) oxygen sensor circuit low voltage (Bank 1 Sensor 1). This code means that the voltage output of O2 sensor located in Bank 1 and Sensor 1 position is lower than expected. This indicates a possible issue with sensor, wiring or fuel system.

Fault Location – HO2S Sensor Oxygen Sensor 1

Possible Causes Code P0131 Honda

1.Failed Oxygen sensor sending low voltage signal to ECM (engine control module)

2.Wiring damage between oxygen sensor and ECM causing low voltage signal to be sent to engine control module.

3.Clogged fuel injector or vacuum leak cause lean air/fuel mixture resulting in low voltage signal from oxygen sensor.

4.Leak in exhaust can cause incorrect air/fuel mixture reading, leading a low voltage signal from oxygen sensor.

5.Failing catalytic converter can cause low voltage signal from oxygen sensor, as catalytic converter is unable to reduce emissions effectively.

Honda P0131 DTC Code Possible Symptoms

Decreased in fuel efficiency, O2 sensor not functioning correctly may cause engine misfire especially during acceleration, engine check light illuminates, engine lack power or may run rough if O2 sensor is not working properly.

How To Fix Code P0131 Honda

1.Inspect wiring between oxygen sensor and ECM(engine control module) for any damage or loose connections. Repair if any damage or issue found.

2.If wiring appear in good condition, replace O2 sensor.

3.Inspect fuel injector for clogged or vacuum leak. If any issue found clean or repair it.

4.Check exhaust for any leaks that could be affecting air/fuel mixture. If any leak found repair it.

5.Inspect catalytic and if found failed replace it. Failed catalytic converter causes low voltage signal.


Its important to have the vehicle inspected and diagnosed by professional mechanic to find and resolve issue associated with p0131 for proper repair.

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