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Air Fuel Ratio (A/F) Sensor Inspection




AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZI 3.7 V6]

A/F Sensor Inspection

1. Warm up the engine to normal operating temperature.

2. Drive the vehicle.

3. Release the accelerator pedal while the engine speed is at 3,000 rpm or more and verify that the following monitor items fluctuate as shown in the figure while the vehicle decelerates. On-Board Diagnostic Test






- VSS
- RPM
- O2S11, O2S21

- If not within the specification, replace the A/F sensor. Air Fuel Ratio (A/F) Sensor Removal/Installation

A/F Sensor Heater Inspection

1. Disconnect the negative battery cable. Removal and Replacement

2. Disconnect the A/F sensor connector.

3. Measure the resistance between A/F sensor terminals C and E.






- If it is not within the specification, replace the A/F sensor. Air Fuel Ratio (A/F) Sensor Removal/Installation

A/F sensor heater resistance
- 1-10 ohms

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