Removing Oxygen Sensor Ahead Of Catalytic Converter

Information 

After installing the oxygen sensor cables, use the PIWIS Tester 9718  to check that the oxygen sensors have not been interchanged. Release the oxygen sensor cable so that the cable can turn when you unscrew or screw in the sensor. Otherwise, the Check Engine light will come on and there may be a change in the vehicle's exhaust gas behaviour.

Information 

After installing the oxygen sensor cables, use the PIWIS Tester 9718  to check that the oxygen sensors have not been interchanged. Release the oxygen sensor cable so that the cable can turn when you unscrew or screw in the sensor. Otherwise, the Check Engine light will come on and there may be a change in the vehicle's exhaust gas behaviour.

1. Disconnect cable plugs on the oxygen sensors ahead of the catalytic converter and expose cables. To do this, trace cable routing to the oxygen sensors ahead of the catalytic converter and disconnect the corresponding cable plugs.
   Fig 1: Identifying Cable Plugs For Oxygen Sensors

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
2. Remove oxygen sensors ahead of catalytic converter-1-  . Detaching oxygen sensor using open-ended wrench (oxygen sensor behind catalytic converter for cylinders 1 to 3 shown) Unscrew both oxygen sensors ahead of the catalytic converter using a ring or open-ended wrench (a/f 22) or using open-end ring wrench Nr.96-3 or open-end ring wrench Nr.98. 
   Fig 2: Identifying Installation Position Of Oxygen Sensors

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   Fig 3: Detaching Oxygen Sensor Using Open-Ended Wrench

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.