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: Wrapping Rag

Courtesy of MAZDA MOTORS CORP.

Fig 2: Locating Connectors And Clips

Courtesy of MAZDA MOTORS CORP.

1. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION .)
2. Lift up the vehicle.
3. Remove the floor under cover. (With floor under cover) (See FLOOR UNDER COVER REMOVAL/INSTALLATION .)
4. Remove the insulator and brace bar. (See EXHAUST SYSTEM REMOVAL/INSTALLATION .)
5. Disconnect the HO2S connector.
6. Remove the clip C.
7. Remove the clip A and clip B from the bracket.
   Fig 3: Removing Clip From Bracket

   Courtesy of MAZDA MOTORS CORP.
8. Remove the HO2S using the SST.
   Fig 4: Removing HO2S Using SST

   Courtesy of MAZDA MOTORS CORP.
9. Install in the reverse order of removal.