2011-2016 GM 6.6L DURAMAX LML FLEECE CP3 CONVERSION KIT FPE-LML-CP3-FF-NP
The Fleece Performance CP3 Conversion Hardware Kit (No Pump) for 2011-2016 LML Duramax is engineered to replace the factory GM CP4 high-pressure fuel system with a CP3-style system favored for durability, reliability, and better fueling characteristics in diesel applications. The CP4 pump used on LML Duramax engines has a documented history of catastrophic failures that often lead to complete fuel system overhaul—making the CP3 conversion one of the most effective preventative upgrades in the diesel performance community. This hardware-only kit supplies all essential components to adapt a Bosch CP3 pump (sold separately) to the 6.6L LML fuel system with OEM-quality precision and fitment. Components are designed to withstand the increased demands of daily driving, towing, and performance enhancements, while still maintaining emissions compliance with 50-state EO# D-834-1 certification. No tuning modifications to FCA regulator tables are required when pairing with a stock CP3, keeping integration simple for most builds.
Kit Includes :
- CP3 to rail high pressure fuel line
- High flow CP3 feed and return fuel fittings
- Preformed feed and return fuel lines
- CP3 mounting adapter
- Dosing injector feed line
- FCA extension harness
- Fuel temperature sensor mounting bracket
- Low pressure fuel feed lines
- Hardware kit
Features & Benefits
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Convert CP4 to CP3 hardware: Provides all necessary non-pump components to adapt a Bosch CP3 pump to LML Duramax fuel system, eliminating the CP4’s weak point and reducing the risk of expensive failures.
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OEM-quality components: Fleece Performance uses molded hoses and high-flow fittings engineered for leak-free fuel delivery and reliable long-term operation.
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50-state emissions compliant: CARB and EPA compliance (EO# D-834-1) ensures legal installation in all 50 states when paired appropriately.
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Maintains stock regulator tables: No FCA regulator table changes required for stock CP3 use, simplifying installation and reducing tuning costs.
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Supports aftermarket lift pumps: Valley feed design accommodates lift pump integration for enhanced fuel delivery and decreased CP3 inlet strain.
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Durability for performance or work use: Preformed lines and robust hardware support higher duty cycles typical of towing, hauling, and modified engines.
Compatibility / Vehicle Applications
This CP3 conversion hardware kit is designed for GM 6.6L LML Duramax diesel engines in:
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2011 Chevrolet Silverado 2500/3500 6.6L LML Duramax
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2012 Chevrolet Silverado 2500/3500 6.6L LML Duramax
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2013 Chevrolet Silverado 2500/3500 6.6L LML Duramax
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2014 Chevrolet Silverado 2500/3500 6.6L LML Duramax
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2015 Chevrolet Silverado 2500/3500 6.6L LML Duramax
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2016 Chevrolet Silverado 2500/3500 6.6L LML Duramax
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Equivalent GMC Sierra 2500/3500 applications (2011-2016)
Used in both daily drivers and performance builds, this hardware kit supports reliability upgrades in light duty and medium duty GM diesel platforms, particularly where factory CP4 failures or future power goals exist.
When paired with a quality Bosch CP3 pump (not included), this conversion lays the foundation for vastly improved fuel system confidence and longevity over the stock CP4 setup.
Shipping Disclaimer:
✔️ We ship via USPS, UPS, and FedEx.
✔️ Carrier selection is based on package size, weight, and destination.
✔️ Expedited shipping options available, call to check freight options
✔️ Orders are processed within 1 business day (Monday–Friday).
✔️ Orders placed on weekends or holidays will be processed on the next business day.
✔️ Tracking information will be provided once the item ships.
✔️ Shipping to PO Boxes, APO/FPO may be limited based on carrier restrictions.
California Proposition 65 Warning:
WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm.
For more information, go to www.P65Warnings.ca.gov
