Main Harness - Universal MPFI

The Universal MPFI Main Harness (model 558-104) is an essential component for any multi-point fuel injection conversion or engine management retrofit project. This harness is ideal for those swapping a carbureted engine to EFI, upgrading an aging fuel system, or building a custom engine bay. It serves as a reliable foundation for fuel injector control and sensor integration.

Designed for flexibility across multiple platforms, the harness eliminates the need for custom wiring fabrication and reduces installation time on complex engine management systems. It features a comprehensive wiring layout engineered to manage multiple fuel injectors, oxygen sensors, and related engine management inputs simultaneously. The robust connectors and shielded signal lines minimize electrical noise, ensuring clean voltage delivery to injectors, which is critical for precise fuel delivery and combustion timing.

Mechanics and engine builders favor this universal harness for LS swaps, EFI retrofit kits, and custom engine bay projects where OEM harnesses may not fit or interface with modern fuel management systems. Its universal design accommodates various engine configurations, making it a versatile choice for any engine builder looking to enhance performance and reliability.