P0131

Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1)




The Heated Oxygen Sensor (HO2S) detects the oxygen content in the exhaust gas and signals the PCM. In operation, the PCM receives the signals from the sensor and varies the duration during which fuel is injected. To stabilize the sensor's output, the sensor has an internal heater. The Primary HO2S (Sensor 1) is installed in the exhaust manifold.

Part 1:

Part 2:

P0131
The scan tool indicates Diagnostic Trouble Code (DTC) P0131: A low voltage problem in the Primary Heated Oxygen Sensor (HO2S) (Sensor 1) circuit.