S&S DIESEL LML-CP3-CARB CP4 TO CP3 CONVERSION KIT (WITH PUMP)The S&S Diesel LML CP3 CARB CP4 To CP3 Conversion Kit (With Pump) from XDP offers a permanent solution to the failure prone CP4 pump in your 2011 2016 GM 6. 6L Duramax LML. S&S Diesel Motorsport specifically developed this kit to address the common CP4. 2 high pressure pump failures that have plagued the LML Duramax engine for years. The S&S solution is to remove the problem before it becomes a problem, by replacing the Bosch CP4. 2 with a tried and