A/F Sensor Heater Inspection

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

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.

CAUTION:

Do not allow flammable objects such as the taping for bundling a wiring harness to come into contact with the exhaust manifold and silencer.

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
Disconnect the A/F sensor connector. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION .)
Measure the resistance between A/F sensor terminals A and E.

Courtesy of MAZDA MOTORS CORP.

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 [normal temperature]