Replacement Fuel Pressure Regulator. Bosch Part # 0928400673. Replacing a faulty fuel pressure regulator may solve the common surging and loping idle that many high mileage Duramax’s have. Trucks exhibiting codes P0090, P0089 and P1093 may be suffering from a failed/failing pressure regulator. This DHD branded regulator has been validated by DHD for performance and durability. It is a OE alternative and is not manufactured by Bosch. Need more parts for your Duramax or pulling truck? Take a look at our website Here!