Heated Oxygen Sensor (Ho2S) Removal/Installation

Special Service Tool (SST)

1: 49 L018 001
2: -
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 a wiring harness to come into contact with the exhaust manifold and silencer.

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.

Fig 1: Wrapping Rag Around Airflow Hole

Courtesy of MAZDA MOTORS CORP.

Fig 2: Clips, Connector And HO2S

Courtesy of MAZDA MOTORS CORP.

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Lift up the vehicle.
Remove the floor under cover. (2WD) (See FLOOR UNDER COVER REMOVAL/INSTALLATION .)
Remove the floor under cover (LH). (AWD) (See FLOOR UNDER COVER REMOVAL/INSTALLATION .)
Remove the insulator and brace bar. (2WD) (See EXHAUST SYSTEM REMOVAL/INSTALLATION .)
Disconnect the HO2S connector.
Remove the clip B from the body.

Fig 3: Clip Of Body
Courtesy of MAZDA MOTORS CORP.
Remove the clip A from the bracket.

Fig 4: Removing Clip From Bracket
Courtesy of MAZDA MOTORS CORP.
Remove the HO2S using the SST.

Fig 5: Removing HO2S Using SST
Courtesy of MAZDA MOTORS CORP.
Install in the reverse order of removal.