Fuel Injection Pressure Regulator Dorman 904-581. Mr Proven Parts is about value and service. We’re a family owned business that is big enough to serve and small enough to care. Striving for perfection is our goal and knowing that were human keeps us humble. If the human side of business causes a issue in the order you can be reassured that we’ll do everything in our power to correct it. WHAT SIDE PART DO I NEED? RIGHT is the PASSENGER SIDE. LEFT SIDE is the DRIVER SIDE. We don’t want you to be disappointed by getting the incorrect side part. Our job is to get you the correct part the first time. Portions of the part information on this page have been provided by WHI Solutions, Inc.