This Duramax LML Fuel Contamination & Bosch CP3 Conversion Kit is a comprehensive solution for 2011–2016 GM 6.6L Duramax diesel trucks designed to address fuel system contamination and catastrophic CP4 pump failure. Featuring a Bosch CP3 high-pressure injection pump, premium Bosch rails and OEM-compatible injectors, this kit delivers enhanced reliability, performance, and long-term durability compared to the stock CP4 pump.
? What’s Included
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? Bosch CP3 High-Pressure Fuel Pump Conversion – Replaces the CP4 pump and eliminates a known failure source common to the LML platform.
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? Bosch or OEM GM Fuel Rails (Driver & Passenger-Side) – Precision-fit rails engineered for exact OE fitment.
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? Set of New OEM Fuel Injectors – High-quality diesel injectors optimized for your Duramax’s common-rail system.
? Key Features & Benefits
✔️ Solves the Duramax CP4 Pump Problem
The factory CP4 high-pressure injection pump on LML Duramax engines is known to shed metal particles upon failure, contaminating the fuel rails, lines and injectors — leading to expensive repairs. Complete contamination kits, like this one, address the entire system rather than just the pump, helping prevent repeat failures.
✔️ Bosch CP3 Conversion for Durability
Bosch CP3 pumps (used on earlier Duramax models) are widely regarded as more robust and reliable than CP4, especially in heavy-duty or high-demand applications. Replacing the CP4 with a CP3 helps avoid repeat system contamination and costly breakdowns.
✔️ Comprehensive System Restoration
Unlike partial repair options, this kit replaces all major contaminated fuel system components — rails, injectors, and pump — ensuring no metal debris remains to damage new parts. This reduces the risk of premature injector failure and improves overall engine performance.
✔️ Precision Fit & High-Quality Components
Bosch is the OEM supplier of fuel rails and injection components. They are engineered to OEM specifications by Bosch, ensuring proper fitment, fuel delivery accuracy, and long-term durability.
? Vehicle Compatibility
Fits:
✔ 2011-2016 GM 6.6L LML Duramax Diesel – Chevy Silverado 2500/3500 HD & GMC Sierra 2500/3500 HD
(This product is engineered specifically for the LML platform where the factory installed the CP4 pump.)
? Why Choose This Kit vs. Stock Replacement
| Feature | Bosch CP3 Conversion Kit | OEM CP4 Replacement Kit |
|---|---|---|
| Addresses CP4 failure root cause | ✔ Yes | ✘ No |
| Reduces future contamination risk | ✔ Yes | ⚠ Only temporarily |
| Includes Bosch conversion pump | ✔ Yes | ✘ No |
| Fits 2011-2016 LML Duramax | ✔ Yes | ✔ Yes |
? Installation & Performance Tips
✔ Inspect and flush your fuel tank and chassis lines prior to installation to remove any residual contamination.
✔ Always use quality diesel fuel and maintenance filters, especially after a contamination event, to protect new components.
✔ Consider pairing with a lift pump and pre-filter upgrade for optimal fuel delivery and longevity.
Kit Includes:
(1) Bosch CP3 Injection Pump - Remanufactured
(8) Genuine Bosch Injectors or New OEM GM / AC Delco
(2) Bosch Fuel Rails or New OEM GM / AC Delco
(1) Bosch Return Circuit - 0445130020
(1) SWAG Performance LML CP3 Pump Conversion Kit
This kit does not incorporate the 9th injector
This kit is the perfect solution when faced with an LML Duramax with a failed CP4 Fuel Injection Pump. It does away with the problematic / fuel system destroying CP4 pump. We recommend running an aftermarket fuel pump / filtration system when upgrading your LML to a CP3.
***FUEL LINES NEED TO BE REPLACED TO PROPERLY FIX AN LML DURAMAX WITH A CP4 PUMP FAILURE. ALL FUEL FILTERS SHOULD BE REPLACED AND IT IS ALSO RECOMMENDED TO CLEAN THE FUEL TANK WHEN PERFORMING THIS REPAIR.
