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Ignitions and Electrical› Computers, Chips, Modules and Programmers

Holley

HP ECU AND HARNESS, FORD MPFI, NTK

$3,228.95 $2,869.95 Save $359.00

SKU: H00E 550-606N

In Stock
In Stock
Ships by Jun 8
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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

This Holley HP EFI ECU and Harness kit (550-606N) is a universal solution designed for Ford V8 Multi-Point Fuel Injection (MPFI) engines. It includes an NTK Oxygen Sensor and a Ford V8 injector harness (EV1 8-Injector). It serves as an alternative to factory ECUs or a replacement for older Holley C950 systems, providing accurate control over fuel and ignition, along with additional controls for nitrous, boost, or water/methanol injection. The ECU is fully potted and uses sealed automotive and marine grade connectors.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandHolley
Part NumberH00E 550-606N
Weight11.01 lb

Videos

Holley EFI ECU Mounting & Wiring

Holley EFI ECU Mounting & Wiring
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All the different holley ecus compared
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Holley - EFI Tech: Main Harness Overview
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How to use a Holley EFI 58x Harness on 24x Engines
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Terminator X EFI for Ford Part 1: Sensors And Relay Wiring
How to Install a Holley Terminator X Max ECU on a Ford Coyote Engine

How to Install a Holley Terminator X Max ECU on a Ford Coyote Engine
Watch This BEFORE You Buy HOLLEY EFI in 2025!

Watch This BEFORE You Buy HOLLEY EFI in 2025!
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Terminator X Full Install and Overview
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Foxbody Mustang Holley Terminator X Install

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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