Product Description
S&S Diesel Motorsport LML-CP3-NO-TUNING-REQ is the drop-in CP4-to-CP3 conversion kit with pump for the 2011–2016 GM Duramax 6.6L LML. Designed for competition/off-road use only, this kit eliminates the failure-prone CP4 and backdates your LML to the proven, “bulletproof” CP3—NO TUNING REQUIRED.
- Direct-fit CP3 conversion with brand-new CP3 pump included
- No calibration changes required for competition/off-road configuration
- All necessary hardware, lines, brackets, and harnesses for a clean install
- Engineered by S&S Diesel Motorsport—common-rail specialists
Fitment
2011–2016 GM Duramax 6.6L LML (Chevrolet Silverado/GMC Sierra 2500HD & 3500HD).
What’s Included
- New CP3 high-pressure fuel pump (LBZ-based, S&S-specified)
- Conversion hardware, brackets, lines, and fittings
- Electrical components/harness for CP3 operation on LML
- Detailed installation instructions (PDF available on S&S site)
Recommended Parts (internal links only)
- Lift Pump Systems (AirDog) for LML
- Lift Pump Systems (FASS) for LML
- High-Quality Fuel Filters & Filter Kits
- LML Fuel Injectors & Injector Install Kits
- S&S CP3 Pump Options & Accessories
Why upgrade? CP4 pumps on LML engines are known for high failure rates that can contaminate and destroy the entire high-pressure fuel system. Converting to CP3 significantly improves durability and fuel system reliability.
Does this kit really require no tuning?
Correct—this specific S&S competition/off-road configuration is designed to run without ECM recalibration. (Note: S&S also offers a 50-state CARB-approved kit that is no-tune as well, and a tuning-required competition variant; this listing is for the no-tune competition kit with pump.)
No. This competition/off-road kit is not emissions-compliant for on-road use. For a 50-state CARB-approved option, see the S&S LML CP3 Conversion Kit w/pump (CARB EO D-756-4).
- 50-State CARB w/pump — No tuning required
- Competition w/pump — No tuning required (this product)
- Competition w/pump — Tuning required
- Hardware-only (no pump)
Will a lift pump help?
Yes—adding a quality lift pump improves supply pressure and filtration, which supports CP3 longevity and consistency in demanding conditions. See our LML-specific AirDog/FASS options above (internal CPP links).
S&S provides a step-by-step installation guide for LML CP3 conversions. We recommend reviewing it completely before starting the job. (See S&S installation PDF.)
Legal Notice: For competition/off-road use only. Buyer is responsible for compliance with all applicable laws and regulations.
