Exergy E04 10504 Improved Stock CP4.2 High Pressure Fuel Injection Pump

The Exergy E04 10504 is an improved stock CP4.2 high-pressure fuel injection pump designed as a direct replacement for factory pumps, supporting stock power levels up to 550+ horsepower without requiring additional modifications or tuning. The OEM CP4 pump is a known weak link in the Duramax LML platform that often leads to catastrophic fuel system damage upon failure, and this improved pump eliminates that concern through precision manufacturing and scientific validation.

Key Features:

• Includes System Saver Inlet Metering Valve with two-layer 10 micron screen mounted on stainless steel frame, replacing the factory single-layer 85 micron screen
• Upgraded heavy-duty FPRV (Fuel Pressure Relief Valve) screen
• Designed by engineers with prior Bosch experience, featuring upgraded internals that resolve failure-prone issues in factory CP4 pumps
• Performance-tested from idle to full power using factory calibration points and additional performance-specific metrics
• No core charge or core return required

This pump serves as a direct replacement for Bosch part numbers 0 445 010 616, 0 986 437 421, and 0 445 010 817, as well as GM part numbers 98077841, 12645102, 12638262, 12658095, and 12661059. For maximum pump performance, a fuel supply of 150 GPH at 8-10 psi per pump is recommended, though a lift pump is not required.