Heated Oxygen Sensor (Ho2S) Removal/Installation

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: Identifying Heated Oxygen Sensor
Courtesy of MAZDA MOTORS CORP.

Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
Lift up the vehicle.
Remove the floor under cover. (See FLOOR UNDER COVER REMOVAL/INSTALLATION .)
Disconnect the HO2S connector.
Remove the insulator and brace bar. (See EXHAUST SYSTEM REMOVAL/INSTALLATION .)

Fig 2: Identifying HO2S Connector Clip
Courtesy of MAZDA MOTORS CORP.
Remove the clip C from the body.

Fig 3: Identifying HO2S Connector Clip
Courtesy of MAZDA MOTORS CORP.
Remove the clip A and clip B from the catalytic converter.

Fig 4: Removing HO2S Connector Clip From Catalytic Converter With Torque Specifications
Courtesy of MAZDA MOTORS CORP.
Remove the HO2S using the SST .
Install in the reverse order of removal.

Fig 5: Removing HO2S Using SST With Torque Specifications
Courtesy of MAZDA MOTORS CORP.