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Merchant Automotive Fuel System Replacement Kit - CP3 Pump, Duramax | 2011 - 2016


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Catastrophic failure on CP3 fuel injection pumps on 2011-2016 LML Duramax trucks will send small metallic debris throughout the entire fuel system. To properly correct this, complete replacement of all affected fuel system components will be required. Our complete solution includes everything that is recommended to be replaced when this type of failure occurs.

This fuel system replacement kit includes a new S&S modified CP3 fuel injection pump, fuel rails, fuel injectors, all of your hard fuels lines, all rubber fuel lines, and all of the gaskets and seals needed to complete the install. This kit requires no tuning and is EPA approved. The CP3 pump is already re-calibrated to match the LML stock CP4 fuel curve. This kit is designed to replace the less reliable CP4 that comes stock on the LML


  • No Tuning Required
  • EPA Approved
  • Recalibrated To Match LML Stock CP4 Fuel Curve


  • New S&S Modified CP3
  • Comprehensive Kit
  • Replaces Less Reliable CP4

Kit Includes

  • CARB CP3 Pump
  • Fuel rails
  • Fuel injectors
  • Fuel lines
  • Master Filter Head Kit (Filters, filter head rebuild kit / spacer, WIF plug, bleeder screw, MA Additive)
  • All Gaskets & Seals Needed For The Job

Duramax LML CP4 Pump Failure

The CP4 fuel injection pump in 2011-2016 Duramax trucks suffer high pressure fuel pump issues due to lack of lubrication. The CP4 was designed to be a more efficient pump than its predecessor, the CP3 pump. However, the CP4 proved to be less reliable than the CP3. An LML CP4 pump failure will present itself with a hard start or no start condition and can result in the following trouble codes: P0087, P0088, P0191, or P128E. This can be confirmed by removing the CP4 pump and fuel pressure regulator and checking for cracks and metal debris on the fuel pressure regulator screen.

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