Genuine OEM. LML / LGH Injector Return Line Assembly. 2011 – 2016 LML / LGH Duramax. If your LML / LGH Duramax will not start, one of the early things to check is the fuel injector return line pressure which must be a minimum of 3 Bar (44 PSI). If the pressure is low and there are no leaks in the fuel return hose assembly, the most likely cause is the return line pressure regulator which is part of the return hose assembly. The piezo injectors utilized in these engines require back pressure in order to function correctly and the return line constant pressure regulator is designed to maintain between 4 and 11 bar (58 – 160 PSI) in the system. Hard starting is often caused by a regulator that is weak. PLEASE READ. We value your patronage. If a delay occurs that is longer than would normally be considered commercially acceptable, we will attempt to contact you. Please take a moment to read it. Local auto parts stores will not pay your travel costs to return a part either. Applications We guarantee our parts to be as described by part number, picture, and verbiage. While we do our best, vehicle applications, however, simply cannot be guaranteed. In most cases, we do not generate application lists. It is the nature of the auto parts business that, in rare cases, a part will not be correct for a certain vehicle even though it “should” fit. This may occur because of errors on application lists, mid-year production changes, changes to the vehicle since it was built, the fact that a car was not built for the US market, etc. If a part does not fit your vehicle, this does not mean the part is not as described. Problems can be solved much more easily when civility is kept intact.