Product Description
Stop CP4 failures before they start. The S&S Diesel LML-CP3-CARB 50-State CP3 Conversion Kit replaces the failure-prone CP4.2 with a proven CP3 high-pressure pump—no tuning required and emissions equipment stays intact. Designed specifically for the 2011–2016 GM Duramax 6.6L LML, this is the clean, reliable way to upgrade your fuel system.
- 50-State CARB Exempt: Legal for use in all 50 states (see EO details on product page)
- No Calibration Needed: Bolt-in hardware and harnessing—drop-in, start, drive
- Complete Kit: Includes CP3 pump, brackets, lines, hardware, extension harnesses, and instructions
- Reliability Upgrade: Replaces CP4 with a durable CP3 to help protect injectors, rails, and lines
Fitment
- 2011–2016 Chevrolet Silverado 2500HD/3500HD – 6.6L Duramax LML
- 2011–2016 GMC Sierra 2500HD/3500HD – 6.6L Duramax LML
What’s Included
- Brand-new CP3 high-pressure fuel pump
- Vehicle-specific brackets, lines, and mounting hardware
- Extension/adapter harnesses for a clean, plug-in install
- Detailed installation instructions
Recommended Parts (CPP Internal Links)
- Lift Pump Systems – Improve supply pressure and CP3 longevity
- Fuel Filters & Service Kits – Keep contaminants out of the high-pressure system
- More S&S Diesel Components – Injectors, rails, and supporting hardware
- Fuel Additives – Extra lubrication and injector cleanliness
Helpful Notes
- This 50-state kit maintains factory after-treatment and does not require tuning.
- We recommend pairing with a quality lift pump for best reliability.
FAQ
Is this kit truly 50-state legal?Yes. It is CARB-exempt for the LML platform. See EO details on the product page for confirmation.
Do I need custom tuning after the swap?
No. This kit is engineered to run on stock calibration—no tuning required.
Will this keep all emissions equipment in place?
Yes. DPF, EGR, and other emissions components remain installed and functional.
What comes in the box?
New CP3 pump, application-specific brackets/lines, hardware, extension harnesses, and installation instructions.
Should I add a lift pump?
Highly recommended. A quality lift pump improves supply pressure, filtration, and CP3 lifespan.
