Heated Oxygen Sensor (Ho2S) Removal/Installation

Special Service Tool (SST)

49 L018 001
O2 sensor wrench

Courtesy of MAZDA MOTORS CORP.

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 the wiring harness to come into contact with the exhaust system such as the exhaust manifold and silencer which reach high temperatures. Otherwise, it could cause fire damage.

NOTE:

If penetrant lubricating spray penetrates the airflow hole of the HO2S, it could cause interference with the HO2S function.
When removing the HO2S, wrap a rag around the lower position so that penetrant lubricating spray does not get sprayed into the airflow hole.

Courtesy of MAZDA MOTORS CORP.

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
Lift up the vehicle.
Remove the floor under cover (LH). (See FLOOR UNDER COVER REMOVAL/INSTALLATION .)
Disconnect the HO2S connector.

Courtesy of MAZDA MOTORS CORP.
Disconnect the clips from the body.

Courtesy of MAZDA MOTORS CORP.
Remove the nuts from the TWC.

Fig 1: TWC Nuts With Torque Specification
Courtesy of MAZDA MOTORS CORP.
Remove the HO2S using the SST.

Fig 2: Heated Oxygen Sensor With Torque Specification
Courtesy of MAZDA MOTORS CORP.
Install in the reverse order of removal.