Removing Heated Oxygen Sensors (HO2S)

Fig 1: Heated Oxygen Sensors

Courtesy of VOLVO CARS OF NORTH AMERICA.

Remove: 

• the engine stabilizer brace between the spring strut stays
• the charge air pipe for the turbocharger (TC) for cylinders 1-3
• the connectors for the front heated oxygen sensors (HO2S). Separate the wiring
• the wiring for the front heated oxygen sensors (HO2S) from the mountings and clips
• The front heated oxygen sensors from the catalytic converter. Use tool 9995543 .
  CAUTION: Note the location of the heated oxygen sensors (HO2S)
• the heat deflector plates
• the 6 nuts for the flange between the turbocharger (TC) and three-way catalytic converter (TWC).

HINT: Use rust solvent on the studs. 

Unhook the three-way catalytic converter (TWC) from the turbocharger (TC).