A: To relieve the pressure of fuel, disconnect the lead from the negative terminal of battery. Clear out any dirt or debris around the fuel lines and the regulator for pressure. Disconnect the vacuum line of fuel pressure regulator. Detach retainer and unplug fuel return line from Fuel Rail. Undo screws that mount pressure regulators for fuel, then take off pressure regulators on fuels. Inspect inner screen of fuel regulator for dirt or debris. In case screen is dirty, replace it with new regulator of fuel pressure. Fix a fresh O ring, apply some engine oil to lubricate it as required by the manufacturer and push it into place. Installation is now complete after reversing the process listed above. Tighten screw on regulator for fuel pressure.