S&S Diesel Ram-CP3- NOTUNE CP4 to CP3 Conversion Kit (With Pump)

The Bosch CP4.2 high-pressure pump found in the 2019–2024 Ram 6.7L Cummins has a well-documented reputation for premature failure — and when it goes, it takes the entire high-pressure fuel system with it via fine metal debris contamination. The S&S Diesel Motorsport® No Tune CP3 Conversion Kit eliminates that risk by replacing the CP4.2 with a proven, bulletproof Bosch CP3NH pump that is internally modified for improved durability, high-speed performance, and tuning-free rail pressure control.

This CARB-compliant (EO #D-756-5) kit pairs the ultra-reliable CP3 with OE-grade components for a factory-quality installation that does not alter engine output — just peace of mind.

Key Features

• Eliminates the failure-prone Bosch CP4.2 high-pressure pump
• Brand-new Bosch CP3NH base pump — internally modified for durability & high-speed performance
• Tuning-free rail pressure control — no tune required
• OE-grade components for a factory-quality install
• CARB-compliant — EO #D-756-5
• Does not change engine output
• Compatible with S&S high-speed competition pumps (sold separately)

Competition Pump Speed Limits

The 6.7L Cummins front cover over-drives the pump at a 1.5:1 ratio. S&S offers high-speed optimized competition pumps to take full advantage:

• 10mm High Speed — 8,000 pump RPM | 5,333 engine RPM
• 12mm High Speed — 7,000 pump RPM | 4,667 engine RPM
• 14mm High Speed — 6,000 pump RPM | 4,000 engine RPM

Fitment Notes

• Fits 2019–2024 Ram 2500/3500 6.7L Cummins
• Install kit available separately for those with existing CP3 pumps (best results with S&S high-speed pumps)