As many LML Duramax owners can attest, the CP4.2 high-pressure injection pump has a high failure rate and that has plagued 2011-2016 GMC Sierras and Chevy Silverados from the beginning. The solution? S&S Diesel Motorsport‘s LML CP3 Conversion Kit that allows you to remove this new failure-prone pump for the tried and true CP3. S&S Diesel Motorsport is one of the leaders in common rail diesel injection and they have recognized the common issues with the new LML Duramax trucks.

CP3 high-pressure pumps have been used for years and continue to show their dominance as far as performance and reliability goes. Unlike the CP3, the CP4 has been the worst part of these LML Duramax engines. When the CP4 pump fails, it will usually take out the entire fuel system. That includes the fuel injectors, rails, and lines and this can get very costly at one time.

Having a kit that can guarantee miles and miles of reliable performance is one thing. To be able to make this kit and comply with the CARB guidelines is a feat in itself. The guidelines that are to be followed are very strict, so props to the guys at S&S Diesel for making this happen.

This includes all hardware necessary to replace the troublesome CP4 with a bulletproof CP3, requires no tuning changes, and still maintains factory emissions control equipment for $2,500 MAP. S&S also offers two other versions of LML CP3 conversion kits for competition trucks which don’t require after-treatment. One tuning required version for $1,780.00 MAP, and one drop-in no tuning required for $2,075.00 MAP.

If you’re interested in what S&S Diesel Motorsport can do for you and your build, be sure and check out their website. Stay tuned to Diesel Army for the latest in parts, builds, and action from our industry. Is your CP4 letting you down? Do you need this kit more than ever? Let us know in the comments below.