Oxygen Sensors before Catalytic Converter

Oxygen Sensors before Catalytic Converter

Removing Heated Oxygen Sensor (HO2S) (G39) bank 1 and Heated Oxygen Sensor (HO2S) 2 (G108) bank 2, removing and installing

Special tools, testers and auxiliary items required

• Ring spanner 7-piece set for oxygen sensor (3337)

- Remove engine cover.





• Intake manifold must be removed to remove oxygen sensor before catalytic converter.

- Remove intake air hose between air filter and throttle valve control module.





- Open fuel supply and fuel return line - 1 and 2 -.





• Engine code BGK has no fuel return line.

- Remove vacuum hose - - arrow - - from fuel pressure regulator (not on engine code BGK).





- Remove vacuum diaphragm - 1 - and hose - 2 - from throttle valve control module.





- Remove electrical connector from Secondary Air Injection (AIR) Solenoid Valve and from throttle valve control module.

- Remove bracket from Secondary Air Injection (AIR) solenoid valve.





- Remove connecting hose of crankcase ventilation.





- Remove vacuum supply - 1 - for intake manifold change-over on intake manifold.

- Disconnect vacuum supply at T-connector - 2 -.





• The illustration is only an example. It shows the 3.7L BFL engine.

- Remove connector from manifold change-over valve.

- Disconnect connector from Hall sensor (bank 1) and from camshaft adjustment valve (bank 2).

- Disconnect all 8-pin connectors from fuel injectors.

- Set both connector strips to the side.

- Remove all socket head cap screws from intake manifold.

- Carefully pull intake manifold up and out. Water connection on throttle valve control module remains connected.

- Set intake manifold to the side, paying attention to the water connection.

• Plug the intake ports of the cylinder head with clean rags.

- Disconnect respective oxygen sensor connector.





2 4-pin connection for heated oxygen sensor (HO2S) 2 (G108) and oxygen sensor (O2S) heater 2 (Z28) before catalytic converter of bank 2
3 4-pin connection for heated oxygen sensor (HO2S) (G39) and oxygen sensor heater (Z19) before catalytic converter of bank 1

- Open all cable ties in order to expose electrical wires.

- Remove respective oxygen sensor with tool from Ring Spanner, 7 piece set (3337) (Illustration shows Heated Oxygen Sensor (HO2S) (G108), bank 2).





Installing

• New oxygen sensors are coated with assembly paste; the paste must not get into slots of oxygen sensor body.

• For a used oxygen sensor, only coat threads with hot bolt paste. This paste must not come into contact with sensor slots.

• Use a lubricant (silicone-free) for installing the intake hose.

• Wires of oxygen sensors must always be secured in the same position when installing so that contact with the exhaust pipe is avoided.

Tightening Specifications





Installation of intake manifold is in reverse order of removal. Note the following.

• Replace gaskets

• All cable ties which are opened or cut open when removing, must be replaced in the same position when installing.

• Secure all hose connections again using original hose clamps.

- Replace intake manifold gaskets, thereby removing the locking bolt - 1 -.

- Note positioning pin - 2 - when installing intake manifold.





- Bolt on intake manifold in diagonal sequence in stages.

- Check fuel system for leaks => [ Fuel system, checking for proper
seal ] Fuel Pressure Regulator and Residual Pressure, Checking.

Tightening Specifications