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Home >> Mazda >> 2017 >> 6 Touring, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Heated Oxygen Sensor (Ho2S) Inspection >> HO2S Heater Inspection
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HO2S Heater Inspection

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: HO2S Wrapped With Rag
G09785553Courtesy 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. Disconnect the HO2S connector.
  5. Measure the resistance between HO2S terminals C and D.
Fig 2: Locating Terminals Of HO2S
G09785554Courtesy of MAZDA MOTORS CORP.