Exergy 1-018-342 LML Duramax Stainless 9th Injector Return Plug with O-Ring

The Exergy 1-018-342 is a precision-machined stainless steel fuel return plug designed specifically for 2011-2016 LML Duramax engines undergoing CP4.2 to CP3 fuel pump conversions. This essential component blocks the unused fuel return loop that is specific to the factory CP4.2 pump but not required when upgrading to a CP3 conversion.

Key Features:

• CNC-machined from stainless steel for superior corrosion resistance and durability
• Includes high-quality O-ring seal for leak-free installation
• Prevents fuel return leaks that can cause hard starting and poor performance
• Direct replacement for unused CP4.2-specific return plumbing
• Precision-engineered threads ensure proper fitment

When converting from the factory CP4.2 high-pressure fuel pump to a more reliable CP3 pump, the CP3 does not utilize the additional return plumbing found on CP4.2-equipped engines. Failing to properly seal this return port can result in fuel system leaks, difficult starting conditions, or reduced engine performance. This plug provides a clean, professional solution to block the non-utilized fuel return loop, ensuring your converted fuel system operates at peak efficiency.

Manufactured by Exergy Performance, a division of Exergy Engineering with roots dating back to 1944 when their former department produced mechanical unit injectors for Detroit Diesel as part of General Motors. Their decades of OE diesel fuel system experience ensures this component meets the highest standards for fitment and reliability.