DTC P1144: Ho2S1 Rich Shift Monitoring - Bank 1 (2.5L): Description
WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.
The heated oxygen sensor 1 is located on the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The heated oxygen sensor 1 has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts the injection pulse duration to achieve the ideal air/fuel ratio. The ideal air/fuel ratio occurs near the radical change from 1V to 0V.