In 4-cylinder engines, unbolt and remove the fuel pressure regulator, releasing pressure in the fuel system, first, disconnect the vacuum hose, followed by the fuel return hose and then unscrewed and removed the unit. To install, it will require undoing all the steps that were used to remove the parts and tightening the bolts to 95 inch lbs. (11Nm). In the case of a 3.0L engine, remove and install using the correct procedure. It is recommended to start with a 4.0L engine, and ease the pressure off of the fuel system, being careful to avoid a rush of pressure and prevent any spillage whilst being mindful of the safety precautions. Keep a Class B-C fire extinguisher in place. The second step is to first remove the vacuum and fuel lines at the pressure regulator followed by removing the 2 or 3 Allen retaining screws in the regulator housing. Installation/Removal Take off the pressure regulator assembly including the gasket and O-ring and remove the gasket, inspection of the O-ring to check that it has no cracks or deterioration. Installation, the gasket mating surfaces should be carefully cleansed to prevent damage, the new O-ring should be lubricated with a light engine oil (not silicone grease), a new gasket and the O-ring installed on the pressure regulator. Install the pressure regulator to the fuel manifold and screw the retaining screws to 6-8 ft. lbs. (8-11Nm) and reconnect the vacuum and fuel lines. Last but not the least, fill and fill fuel, turn ignition switch, ON, OFF, at least 6 times, making sure the ignition switch remains on not less than five seconds, and verify any leakage.