DTC P2271-00: O2 Sensor Stuck Rich - Bank1 Sensor 2: General Description

The Heated Oxygen Sensor (HO2S) (Bank1, Sensor2) 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. It produces a voltage between 0V and 1V. This 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 HO2S (Bank1, Sensor1)