1. Remove the upper intake manifold. Refer to Upper Intake Manifold Replacement in Engine Mechanical-4.3L.
2. Remove the fuel pressure regulator retaining clip (5).
3. Twist and pull the fuel pressure regulator (6) in order to remove the regulator from the housing using a shop towel to catch any spilled fuel.
4. Remove and discard the regulator seal O-ring (10).
5. Remove and discard the regulator filter (9).
6. Remove and discard the regulator seal O-ring (8).
7. Remove and discard the regulator seal backup ring (7).
8. Cover the fuel pressure regulator housing to prevent contamination from entering the fuel system.

Important: If the fuel pressure regulator is to be reinstalled, inspect the filter screen for contamination. If the filter screen is contaminated, replace the regulator.

1. Lubricate the NEW O-rings with clean engine oil.
2. Assemble the following NEW parts to the fuel pressure regulator:

•	Backup ring (7)

•	Regulator seal O-ring (8)

•	Regulator (9)

•	Regulator seal O-ring (10)

3. Install the fuel pressure regulator with the vacuum tube pointing down.
4. Install the fuel pressure regulator retainer clip (5).
5. Install the upper manifold. Refer to Upper Intake Manifold Replacement in Engine Mechanical-4.3L.
6. Tighten the fuel fill cap.
7. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
8. Inspect for leaks.

8.1.	Turn the ignition ON, for 2 seconds.

8.2.	Turn the ignition OFF, for 10 seconds.

8.3.	Turn the ignition ON.

8.4.	Inspect for fuel leaks.