When going up grade pulling fifth wheel camper, check engine light will occassionally luminate. ODB II code is p0087. DIC shows "change fuel filter" or engine power is reduced. Fuel filter changed 5k miles ago. Filter tested and within specs. Only happens when pulling load up grade, but doesn't happen every time. Dealer checked truck and told me all diagnostics normal. But still happens periodically. HELP please.
2008, 6.6 Duramax LMM, Allison 6 speed
P0087 Important: If the Change Fuel Filter Warning light is ON with DTC P0087, inspect the fuel filter for a restriction or contamination. A restricted, kinked, or damaged fuel supply line may cause DTC P0087 to set. If a low fuel condition is present and DTC P0087 sets, inspect the fuel sender pickup tube for damage or perforations. Water or gasoline contamination of the fuel may cause this DTC to intermittently set. Refer to Contaminants-in-Fuel Diagnosis. When ambient temperatures are below 0°C (32°F), the fuel tank pickup screen may be iced over from water in the fuel tank. When power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely affect the fuel system components. If the fuel pressure relief valve is not torqued correctly, the valve will leak fuel into the fuel return system causing this DTC to set. The fuel pressure relief valve uses a bite type seal, and proper torque is essential for valve to rail sealing. Refer to Fastener Tightening Specifications. High fuel injector return flow may cause this DTC to set. The addition of fuel system enhancements, such as auxiliary fuel tanks or add on fuel filters may relate to driveability complaints.
what is the year and engine size?