ACDelco GM Original Equipment Fuel Injection Pressure Regulators are mechanical valves that control fuel pressure in the fuel injector rail, and are GM-recommended replacements for your vehicleÆs original components. Their spring-loaded valves return excess fuel back to the fuel tank. These original equipment fuel injection pressure regulators have been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors. ? WARNING: Cancer and Reproductive Harm - https://www.P65Warnings.ca.gov