Heated Oxygen Sensor (Ho2S) And Catalyst Monitor Sensor - 3.0L (4V) Removal/Installation

Fig 1: HO2S, Catalyst Monitor Sensor With Torque Specifications -- 3.0L (4V) Replacement Components

Courtesy of MAZDA MOTORS CORP.

1. With the vehicle in NEUTRAL, position it on a hoist. See LIFTING .
2. Remove the 7 bolts (5 shown) and the LH splash shield.
   • To install, tighten to 10 N.m {1.0 kgf.m, 89 in.lbf}.
   Fig 2: Locating LH Splash Shield Bolts

   Courtesy of MAZDA MOTORS CORP.
3. Disconnect the heated oxygen sensor (HO2S) and the catalyst monitor sensor electrical connectors.
4. Using the special tool, remove the HO2S and the catalyst monitor sensor.
   • To install, tighten to 48 N.m {4.9 kgf.m, 35 ft.lbf}.
   NOTE:

   • If necessary, lubricate the HO2S and catalyst monitor sensor with penetrating and lock lubricant to aid in removal.
   Fig 3: Identifying Special Tool

   Courtesy of MAZDA MOTORS CORP.
5. To install, reverse the removal procedure.
   NOTE:

   • Apply a light coat of anti-seize lubricant to the threads of the HO2S and the catalyst monitor sensor.