DTC P2270-00: O2 Sensor Stuck Lean - Bank 1 Sensor 2: General Description

The oxygen sensor is a thin film laminated sensor made up of zirconia and alumina. Mounted on the front and rear of the MCC of the exhaust pipe, the voltage generated by the oxygen concentration in the exhaust gas is transmitted to the Powertrain Control Module (PCM). The rear Heated Oxygen Sensor (HO2S) is mounted on the rear side of the catalytic converter (warm-up catalytic converter) or in the rear exhaust pipe, which is able to detect catalyst efficiency. The rear HO2S produces a voltage between 0V and 1V. This rear HO2S is used to estimate the oxygen storage capability. If a catalyst has good conversion properties, the oxygen fluctuations are smoothed by the oxygen storage capacity of the catalyst. If the conversion provided by the catalyst is low due to aging, poisoning or misfiring, then the oxygen fluctuations are similar to signals from the front oxygen sensor.