Important: Three styles of fuel pressure regulators and fuel rails will be used in this model year. Each regulator has a different "footprint" that consequently changes the size of the receiving port in the fuel rail. The regulator retaining clips are specific to each rail-regulator design and cannot be interchanged.

1. Remove the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement in Engine Mechanical - 4.8L, 5.3L, and 6.0L.
2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
3. Disconnect the fuel pressure regulator vacuum line.
4. Clean any dirt from the fuel pressure regulator retainer and the surrounding area.
5. Remove the fuel pressure regulator retainer (8).
6. Remove the fuel pressure regulator (9).
7. Ensure none of the following parts are still in the fuel rail:

•	Backup ring (10)

•	Regulator Seal O-ring (11)

•	Regulator filter (12)

•	Regulator seal O-ring (13)

1. Ensure that the NEW fuel pressure regulator retainer is the correct one.
2. The tabs (1) are used on the straight vacuum port retainer (2), and the E85-straight vacuum port retainer (3).
3. The angle vacuum port retainer (4) has no tabs.



4. Install the following parts onto the fuel pressure regulator (9), if necessary.

•	Backup ring (10)

•	Regulator seal O-ring (11)

•	Regulator filter (12)

•	Regulator seal O-ring (13)

5. Lubricate the fuel pressure regulator O-rings (11, 13) with clean engine oil.
6. Install the fuel pressure regulator (9).

Important: Whenever the fuel pressure regulator is removed from the fuel rail NEW O-rings and a NEW retaining clip should be used on reinstallation.

7. Install the NEW fuel pressure regulator retainer (8).
8. Connect the fuel pressure regulator vacuum line.
9. Tighten the fuel filler cap.
10. Inspect for leaks.

10.1.

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

10.2.

Turn OFF the ignition for 10 seconds.

10.3.

Turn ON the ignition, with the engine OFF.

10.4.

Inspect for fuel leaks.

11. Install the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement in Engine Mechanical - 4.8L, 5.3L, and 6.0L.