Resistance Inspection (HO2S Heater)

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 wiring harness to come into contact with the exhaust manifold and silencer.

Disconnect the negative battery cable. (Refer to NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION .)
Lift up the vehicle.
Remove the insulator. (Refer to EXHAUST SYSTEM REMOVAL/INSTALLATION .)
Disconnect the HO2S connector.
Measure the resistance between HO2S terminals C and D.

Fig 1: Locating HO2S Terminals
Courtesy of MAZDA MOTORS CORP.
- If not as specified, replace the HO2S. (Refer to HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION .)
  HO2S heater resistance
- 2-50 ohms