A/F Sensor Heater Inspection

Disconnect the A/F sensor connector.
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 1-10 ohms

Fig 1: Locating A/F Sensor
Courtesy of MAZDA MOTORS CORP.