Front HO2S current inspection

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Warm up the engine to normal operating temperature.
Using the WDS or equivalent, monitor the following:
- Vehicle speed (PID: VSS)
- Engine speed (PID: RPM)
- Front HO2S current (PID: O2S11)
Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3,000 rpm or more.
Verify that the front HO2S current (PID: O2S11) is 0.25 mA or more while decelerating as shown in the figure.

Fig 1: Identifying VSS, RPM And O2S11 Graph
Courtesy of MAZDA MOTORS CORP.
- If not within the specification, inspect the HO2S for an open or short circuit. (See FRONT HO2S CIRCUIT OPEN/SHORT INSPECTION (SENSOR) .) Then if there is no malfunction in the wiring harness, replace the front HO2S.