Duramax 6.6L LGH Fuel Contamination Kit 11-16 GM 6.6L Duramax LGH XD518 XDPThe XDP Duramax 6. 6L LGH Fuel Contamination Kit XD518 includes the items you need to repair the fuel system in your 2011 2016 GM Duramax 6. 6L LGH after a CP4 injection pump failure. The factory CP4 pump is a known weak point and often fails in a catastrophic nature. As a result, debris from the CP4 failure typically contaminates the fuel injectors, fuel injector lines, fuel rails, and other fuel system plumbing. To repair the failed pump and