Fleece Performance LML Duramax CP3 Conversion Kit with CP3 Pump (FPE-LML-CP3-WP) 2011–2016 6.6L GM Duramax LML | Complete CP4 to CP3 Swap Kit

Stop Worrying About Catastrophic CP4 Failures

The factory CP4 high-pressure fuel pump on 2011–2016 LML Duramax engines is a well-known weak point. When it fails (and it often does), it can send metal debris through the entire fuel system — destroying injectors, rails, lines, and the pump itself. Repairs frequently run into the thousands of dollars.

The Fleece Performance FPE-LML-CP3-WP kit solves this problem once and for all by converting your LML from the problematic CP4 to the proven, reliable Bosch CP3 pump used successfully for years in LBZ and LMM Duramax trucks.

This is the complete “With Pump” version — it includes a brand-new genuine Bosch CP3 high-pressure pump plus every fitting, hose, bracket, and line needed for a clean, OEM-quality installation.

Key Benefits

• Dramatically improved reliability — The CP3 is far more robust than the CP4
• Better fueling capability than the stock CP4
• No tuning required — Works with the factory ECM
• 50-state legal — CARB EO# D-834-1
• OEM fit and finish with Fleece’s exclusive preformed molded hoses
• Designed to work with or without an aftermarket lift pump
• Patent-protected design (US Patent D1023736)

What’s Included in the FPE-LML-CP3-WP Kit

• New Bosch CP3 high-pressure injection pump (LBZ/LMM style)
• CP3-to-rail high-pressure fuel line
• High-flow CP3 feed and return fittings
• Fleece exclusive preformed molded feed & return fuel hoses
• CP3 mounting adapter
• Dosing injector distribution block with feed and return lines
• FCA (Fuel Control Actuator) extension harness
• Low-pressure fuel feed line
• Fuel temperature sensor mounting bracket
• Valley feed line support for aftermarket lift pumps
• Complete hardware kit

Important Application Notes

• Lift Pump Compatibility: If you are running an aftermarket lift pump, feed pressure to the CP3 should not exceed 5–6 PSI for optimal performance.
• 1-year limited parts warranty from Fleece Performance.

Vehicle Fitment

• 2011–2016 Chevrolet Silverado 2500HD / 3500HD 6.6L Duramax LML
• 2011–2016 GMC Sierra 2500HD / 3500HD 6.6L Duramax LML

Why Full Fried Diesel Recommends This Kit

This is the cleanest, most complete CP3 conversion solution available for the LML platform. Whether your truck is stock or modified, swapping to a CP3 gives you peace of mind and a stronger foundation for future performance upgrades.