To remove and install pressure regulator for 2.3L 4-Cylinder and 2.8L 6-Cylinder engines: Get started by relieving the fuel system pressure and disconnecting the negative battery cable. Next, remove the fuel lines and vacuum line from the pressure regulator, and finally, retaining bolts or nuts that hold the pressure regulator to the bracket. To install the pressure regulator, insert the pressure regulator in the bracket and screw in the bolts or nuts and then reconnect the vacuum line and fuel lines, followed by the negative battery cable. Start the vehicle and check for leaks and to make sure fuel pressure is correct, shut the engine off and try to place the protective cover on the fuel rail. For the 2.9L 6 Engine and 2.3L and 2.4L 5 Engines, begin by venting the fuel system pressure and disconnecting the negative battery cable. Remove the fuel rail assembly, vacuum line and fuel lines from the pressure regulator then remove the regulator from the fuel rail. When installing, lubricate the O-ring on the pressure regulator and O-rings on the injectors and install a new pressure regulator making certain the O-ring seats are properly seated. Tighten the fuel lines to the regulator, reconnect the vacuum line and reinstall the fuel rail assembly, keeping the O-rings seated in place. Reconnect the negative battery cable and start the car to check for leaks, check the fuel pressure, and finally shut off the car engine and install the fuel rail protective cover.