Mazda 2: Air Fuel Ratio (A/F) Sensor
AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION
WARNING:
- A hot engine and exhaust system can cause severe burns. Turn off the
engine and wait
until they are cool before removing the exhaust system.
1. Disconnect the negative battery cable.
2. Remove the air cleaner cover. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION).
3. Disconnect the A/F sensor connector.
4. Remove the A/F sensor using the SST.

5. Install in the reverse order of removal.
AIR FUEL RATIO (A/F) SENSOR INSPECTION
A/F Sensor Inspection
1. Warm up the engine to normal operating temperature.
2. Using the M-MDS, monitor the following:
- Vehicle speed (PID: VSS)
- Engine speed (PID: RPM)
- A/F sensor current (PID: O2S11)
3. Drive the vehicle and decelerate the engine speed by releasing the
accelerator pedal fully
when the engine speed is 3,000 rpm or more.
4. Verify that the A/F sensor current (PID: O2S11) is 0.25 mA or more while
decelerating as
shown in the figure.

- If not as specified, replace the A/F sensor. (See AIR FUEL RATIO (A/F)
SENSOR REMOVAL/INSTALLATION).
A/F Sensor Heater Inspection
1. Disconnect the A/F sensor connector.
2. Measure the resistance between A/F sensor terminals C and D.

- If not as specified, replace the A/F sensor. (See AIR FUEL RATIO (A/F)
SENSOR REMOVAL/INSTALLATION).
A/F sensor heater resistance
READ NEXT:
HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION
WARNING:
A hot engine and exhaust system can cause severe burns. Turn off the
engine and wait
until they are cool before removing the exhaust syst
CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION
CAUTION:
When replacing the CKP sensor, make sure there is no foreign material on
it such as
metal shavings. If it is installed with foreign
CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION
CAUTION:
When replacing the CMP sensor, make sure there is no foreign material on
it such as
metal shavings. If it is installed with foreign ma
SEE MORE:
DTCs are recorded in the PCM and instrument cluster when a malfunction
is detected.
The stored DTCs can be verified using the flashing pattern of the security
light and M-MDS.
There are some DTCs which cannot be verified using the security light.
Verify the DTCs that were detected using t
System Malfunction Location
Detection Condition
WARNING:
Detection conditions are for understanding the DTC outline before
performing an
inspection. Performing an inspection according to only the detection
conditions may
cause injury due to an operating error, or damage the system. When
p
© 2016-2023 Copyright www.ma2auto.com
