DTC P0131: Linear O2 Sensor Circuit Low Input (Bank 1 Sensor 1): Description

The linear oxygen sensor is mounted on the front side of the Catalytic Converter (warm-up catalytic converter) or in the front exhaust pipe, which detects a wide range of air/fuel ratio in the exhaust gas from rich to lean regions. This linear oxygen sensor produces a current that corresponds to a specific air/fuel ratio. The ECM monitors this signal and determines whether the air/fuel mixture is rich or lean. The ECM constantly monitors the H02S and increases or decreases the fuel injection duration by using the HO2S signal, which is called closed-loop fuel control operation.