1999-04 Mustang Holley 4V Engine Management System 4.6/5.4 by Holley

Details   |  Description
  • Holley Mustang 4V Engine Management System (99-04) 4.6 5.4 550-617
Holley Mustang 4V Engine Management System (99-04) 4.6 5.4 550-617

Take your 1999-2004 Ford Mustang's 4V engine to the next level with this plug & play engine harness!

Item #HLY-550617
MPN# 550-617

Everyday Low Price: $1,900.95

  Ships from supplier by Wednesday, July 25

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  • Designed Specifically For 4V 1999-2004 Engines
  • Plug & Play With Factory Sensors
  • Plug & Play With Factory Actuators


  • Connectors for Holley Fuel Pressure and Oil Pressure sensors
  • Connectors for expanded Inputs and Outputs
  • Complete plug and play kit includes HP ECU

What's in the Box

  • (1) HP EFI ECU & Harness
  • (1) All Necessary Hardware

Product Description

Holley's 4V Engine Management System
If you are looking to take your 1999-2004 Ford Mustang's 4V engine to the next level, look at this Holley EFI ECU Harness. This Holley HP EFI system is equipped with 4 programmable inputs and 4 programmable outputs that are ideal for 1999 to 2004 New Edge Mustang with a single power adder. This feature allows you to configure the system to support a wide range of controls including boost control, progressive nitrous, water/meth injection, speed inputs, fuel pump control, AC inputs, timing retard inputs and various other uses. When selecting an ECU, you need to ensure your planned controls can be run with the 4 inputs and 4 outputs as certain combinations may use more I/Os than are available. ECU is certified to ISO 8846, SAE J1171 & United States Coast Guard Requirements for Ignition Protection & Fire Resistance.

This part is legal for use on Uncontrolled (Non-Emissions Controlled) Vehicles or Racing Vehicles.

The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles:

1965 and older U.S. manufactured California Certified vehicles
1967 and older U.S. manufactured Federally Certified vehicles
1967 and older Foreign manufactured vehicle
Racing Vehicles are vehicles that are used exclusively for racing or other forms of competition that are not registered and that may never be used on the street.

- Fits 1999-2004 Ford Mustang - 4V Modular Engines

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Vehicle Applications

Ford Mustang - 1999 (99) - 2000 (00) - 2001 (01) - 2002 (02) - 2003 (03) - 2004 (04)

About This Brand

Holley, The Heart & Soul of Performance.

For over 100 years Holley has been proven to be an industry leader by providing Mustang enthusiasts and racers with the high performance carburetors , intake manifolds, cylinder heads, and other quality performance components needed for today's competition. Holley's performance Mustang parts are perfect for any daily driven or high horsepower race car.

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