Engineered Application

The Alliant Power AP54821 is a comprehensive fuel contamination kit purpose-built for 2019–2022 GM 6.6L Duramax L5D engines found in Chevrolet/GMC 4500HD, 5500HD, and 6500HD trucks. Specified as a direct replacement that meets or exceeds OE requirements, this kit is designed to restore fuel system integrity after contamination events or major component failures, helping fleets and service operations return vehicles to service with confidence and consistency.

Complete Kit Contents

AP54821 consolidates all primary hard parts required for a thorough remediation: eight injectors, one high-pressure fuel pump, two fuel rail cores, plus associated high-pressure lines and components. Replacing these assemblies together helps eliminate residual debris paths and ensures matched, OE-spec performance across the fuel circuit. Application-specific components and OE-form-factor interfaces support accurate installation on the L5D architecture, minimizing rework and simplifying parts sourcing by providing a single, model-correct solution.

Warranty and Core Handling

Alliant Power backs this kit with a 3-year, unlimited-mileage warranty covering critical fuel system components. To receive core credit, the eight injectors, one pump, and two rail cores must be returned in their original manufacturer packaging; a $1400 core surcharge applies until acceptable cores are received and processed. Consolidated content, clear core policy, and extended warranty coverage provide a reliable, OE-level path to restoring L5D fuel systems following contamination.