Fuel Composition Sensor Replacement 5.3L (L59) Engine

1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
2. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Disconnect the fuel composition sensor electrical connector.



4. Remove the fuel line retainers (1).
5. Disconnect the fuel composition sensor fuel lines. Refer to Metal Collar Quick Connect Fitting Service .



6. Remove the fuel composition sensor bracket nuts.
7. Remove the fuel composition sensor.
8. If required, remove the fuel composition sensor bolts and remove the sensor from the bracket.

Notice: Refer to Fastener Notice in the Preface section.




1. If required, install the fuel composition sensor to the bracket and install the bolts.

Tighten
Tighten bolts to 10 N·m (89 lb in).

2. Install the fuel composition sensor.
3. Install the fuel composition sensor bracket nuts.

Tighten
Tighten nuts to 17 N·m (13 lb ft).




4. Connect the fuel composition sensor fuel lines. Refer to Metal Collar Quick Connect Fitting Service .
5. Install the fuel line retainers (1).



6. Connect the fuel composition sensor electrical connector.
7. Lower the vehicle.
8. Use the following procedure in order to inspect for leaks:

•	Turn the ignition ON, with the engine OFF, for 2 seconds.

•	Turn the ignition OFF for 10 seconds.

•	Turn the ignition ON, with the engine OFF.

•	Inspect for fuel leaks.