Product Description
S&S Diesel LML-CP3-TUNING-REQ is the proven CP4 → CP3 conversion kit with pump for the 2011–2016 GM Duramax 6.6L LML. Built for competition/off-road use only, this version requires custom tuning and is intended for trucks without DPF/EGR/after-treatment.
Why Upgrade from CP4 to CP3?
- Addresses the LML platform’s CP4 high-pressure pump failure risk with a robust CP3 solution (S&S category notes).
- Includes premium hardware and OE-grade lines/fittings for a clean install.
- Pairs with competition calibrations for consistent rail pressure and fueling under load.
Fitment
- 2011–2016 Chevrolet Silverado 2500HD/3500HD 6.6L Duramax LML
- 2011–2016 GMC Sierra 2500HD/3500HD 6.6L Duramax LML
- RPO: LML (CP4-equipped from factory)
- Notes: Competition/off-road use only; tuning required; not for vehicles with DPF/EGR/after-treatment installed.
What’s Included
- Brand-new S&S CP3 pump (competition configuration)
- High-quality adapter lines, fittings, and hardware for CP4→CP3 conversion
- Electrical extensions/adapters as required for LML application
- Install instructions (see S&S documentation for CP3 conversion guidance)
Recommended Parts (Internal Links Only)
- CP3 PUMPS & UPGRADES – pair with SS/10/12/14mm pumps for power goals.
- LIFT PUMPS (AIRDOG & FASS) – ensure steady low-pressure supply under load.
- FUEL FILTERS & FILTER HEADS – protect your high-pressure system.
- DURAMAX LML INJECTORS (2011–2016) – stock or performance matched sets.
- FUEL RAILS, LINES & FITTINGS – replace any compromised components after a failure.
Helpful Notes
- This Tuning-Required kit is different from the 50-State CARB and No-Tune Competition variants. If you need emissions-intact/DPF vehicles, see a 50-STATE CARB CP3 KIT.
- Custom calibration is mandatory for proper rail pressure control with this kit.
- For daily-driven/emissions-equipped trucks, choose the CARB or no-tune alternatives instead.
No. This is a competition/off-road use only kit intended for vehicles without emissions after-treatment (no DPF/EGR).
FAQ: Do I need custom tuning?Yes. This version explicitly requires custom tuning (“recal required”) on the LML platform.
FAQ: What’s the difference between this and the 50-State kit?The 50-State kit is CARB-exempt, includes a CP3, requires no tuning, and maintains factory emissions equipment; This competition kit requires tuning and is not emissions-legal.
FAQ: What if I had a CP4 failure?Inspect/replace contaminated components (rails, lines, injectors, tank, filters). See our internal categories for rails/lines and LML injectors. Thorough decontamination is critical for warranty and longevity.
FAQ: Will an aftermarket lift pump help?Yes, a quality lift pump can improve supply and protect the CP3 under heavy load. See Lift Pumps (Airdog/FASS).
Disclaimer: For competition/off-road use only. Buyer is responsible for compliance with local, state, and federal laws.
