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P0131

Overview

Code

P0131

Code Type

P

Code Class

P0

System

Engine, Emissions

Severity Level

Medium

Emissions Related

true

Drivability Impact

Minor

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0131 indicates that the oxygen sensor circuit voltage is lower than expected for Bank 1 Sensor 1, as detected by the ECM

Symptoms

Check Engine Light illuminated; Poor fuel economy; Rough idle

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

The upstream oxygen sensor is critical for fuel mixture adjustment and emissions control

Possible Causes

Faulty oxygen sensor; Exhaust leaks upstream of the sensor; Wiring short to ground

Diagnostic Steps

1 Confirm the fault code; 2 Inspect sensor wiring and connectors; 3 Check for exhaust leaks; 4 Monitor live O2 voltage; 5 Replace the oxygen sensor if voltage remains low

Drive Safety Notes

Driving is possible, but emissions and fuel efficiency will be affected

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