S&S Diesel Motorsport — the world leader in common-rail diesel injection — developed the only CARB-compliant 50-state CP3 conversion available for the LML Duramax. The solution is simple: remove the CP4.2 problem before it becomes a problem by replacing it with a proven, bulletproof CP3 high pressure fuel pump.

The CP4.2 is the Achilles heel of the LML Duramax. High failure rates are well documented, and when the CP4.2 fails it commonly destroys the entire high-pressure fuel system with it — injectors, rails, and lines — resulting in repair bills that can easily reach $10,000 or more. The S&S CP3 conversion eliminates that risk entirely.

The CARB-compliant kit (EO #D-756) includes all hardware necessary to replace the CP4.2 with a bulletproof CP3, requires no tuning changes, and maintains all factory emissions control equipment. Additional configurations are available for competition use.

Available configurations:

LML-CP3-CARB — 50-State LML CP3 Conversion with Pump. No tuning required. Emissions intact. CARB compliant EO #D-756. The street legal, plug-and-play solution for LML owners who want maximum reliability without any compliance concerns.

LML-CP3-NoTuningReq'd — LML CP3 Conversion with Pump. No tuning required. No emissions intact. Competition use only. For builds where emissions equipment has been removed and no tune is needed.

LML-CP3-TuningReq'd — LML CP3 Conversion with Pump. Tuning required. No emissions intact. Competition use only. For fully built competition applications requiring custom calibration to maximize the CP3 conversion.

LML-CP3-w/o-pump — LML CP3 Conversion without Pump. Kit includes all hardware minus the pump. Add your desired S&S pump — SuperSport, 10mm, 12mm, or 14mm — or provide your own. Everything needed for the conversion is included except the pump itself.

Note: The competition-use configurations (NoTuningReq'd and TuningReq'd) are for off-road and competition use only. Emissions equipment must remain intact for street legal operation.