DTC P0134 & P0154: Ho2S Bank 1 & 2 Sensor 1 - Insufficient Activity: Description

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

The Heated Oxygen Sensor (HO2S) is a sensor used to detect oxygen-content in the exhaust. The Powertrain Control Module (PCM) supplies the sensor with a signal circuit and a ground circuit. The PCM supplies a bias voltage between the circuits. The sensor varies the voltage based on the oxygen content in the exhaust. When the exhaust stream is lean (more oxygen), the sensor produces a low voltage signal. When the exhaust stream is rich (less oxygen), the sensor produces a high voltage signal. The PCM monitors the HO2S signal during Closed Loop. In order to correct for rich or lean conditions, the PCM adjusts the injector pulse width. This DTC indicates that the HO2S voltage remained at or near the bias voltage for a calibrated period of time.