SKU: 25982102966

Holley HP EFI ECU and Harness Kits 550-606N

Sale price$1349.97 Regular price$1499.97
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  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 15 - Jul 20

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Description

Holley HP EFI ECU and Harness Kits 550-606NHP ECU AND HARNESS, FORD MPFI, NTK Looking for a alternative for your stock or built late model factory FORD EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine

HP ECU AND HARNESS, FORD MPFI, NTK

Looking for a alternative for your stock or built late model factory FORD EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost or water meth.

Features:

  • Optional 5.7” full-color touchscreen LCD allows easy on-the-fly tuning,data-logging or can be used as an easy to see graphical gauge panel
  • Eight sequentially driven 8:2 peak and hold injector drivers, capable of driving up to 16 low or high impedance injectors as a standard feature. Multiple staged injector strategies
  • Eight channel Distributorless Ignition (DIS)outputs capable of directly driving “Smart” ignition coils or Holley DIS coils. Will drive 2 wire coils with the addition of PN 554-112 high current coil driver module
  • Plug and Play control of factory GM 24x and 58x LSx engines
  • Integrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors
  • Internal data-logging standard with a huge 2GB of memory
  • 4 Stage progressive nitrous control
  • Turbo boost control
  • Integrated water/methanol injection control
  • Self-tuning fuel table strategy greatly simplifies tuning process
  • Individual cylinder fuel and spark control allows you to unlock your engine’s potential
  • Works with 4, 6, 8 cylinder engines
  • Unique lb/hr based fueling strategy greatly simplifies and commonizes tuning
  • Advanced idle, closed loop, and enrichment strategies allow for very stable operation
  • ECU is fully potted and can be mounted in the engine compartment or interior
  • Sealed automotive and marine grade connectors
  • Allows for use of common OEM sensors as well as customer sensor calibration input
  • Ignition Plug and Play with GM 24x and 58x LSx engines, GM HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. New Plug and Play applications in process. Custom settings can be configured to allow many other applications
  • 1-5 Bar MAP sensor capability
  • Two channel knock control sensor Inputs for both one or two wire knock sensors
  • Dedicated fuel and oil pressure inputs
  • Controls both stepper and PWM Idle Air Control (IAC) motors
  • Speed density, Alpha-N, or combination fueling strategies
  • 4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use
  • 4 Stage nitrous oxide control
  • Fully featured nitrous control eliminates the need for a separate nitrous controller device
  • Can be configured “Wet” or “Dry” with closed loop feedback
  • Progressive control based on time, RPM, or boost, requires part # 554-111
  • Lean or rich safety cutoff
  • Full timing retard/control configurability per stage based on RPM or time
  • Integrated Water/Methanol injection control
  • Uses Holley Water/Meth solenoids specially designed and calibrated for use with this EFI system to allow the user to enter Water/Meth flow as a percentage of fuel injector flow
  • Includes NTK wideband oxygen sensor

Application

  • Universal

Specs

Brand Holley EFI
Emission Code 3
Ignition Type Coil - (No Timing Control)
  Ford TFI
  Holley Dual Sync Distributor
Injector Connector Jetronic / Minitimer (Bosch)
Product Type HP EFI Kit
Part Number 550-606N
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 25982102966

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Kelly Klimczak
Pawtucket, US
★★★★★ 4
Nice pillow
Size: Standard (Mid Loft), Number of Items: 1
Nice but found better
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Reviewed in the United States on April 16, 2026
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Ellen C.
Belleville, US
★★★★★ 5
Comfortable Pillow!
Size: Standard (Mid Loft), Number of Items: 1, Size: Standard (Mid Loft), Number of Items: 1
For many years, I always bought the same brand latex foam pillow. Unfortunately, it's not made anymore so I took a chance with something new. I'm glad I picked this one! Very comfortable and I like the medium firmness. Not too soft or too firm, perfect for me. There is a very slight odor but it is not overpowering at all and I know it will dissipate over time. I will be purchasing another one soon!
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Reviewed in the United States on April 21, 2026
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Patricia A Weston
Pawtucket, US
★★★★★ 5
Perfect pillow
Size: Standard (Mid Loft), Number of Items: 1
I like this pillow. Fits great for latex.
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Reviewed in the United States on May 3, 2026
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Bob
Lowell, US
★★★★★ 3
Very good
Size: Standard (Mid Loft), Number of Items: 1
Excellent pillow. Soft but medium support. Fell asleep on it right away and it stays cool. Like sleeping on a cloud.
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Reviewed in the United States on August 1, 2025
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Chris
Draper, US
★★★★★ 5
A Good Night’s 💤
Size: Standard (Mid Loft), Number of Items: 1
I’ve bought many pillows over the years and this pillow is by far the best for me. I am a back and side sleeper. Finally wake up without a headache or neck discomfort. I bought the medium standard. Just the right consistency. Not to soft not to firm. Stay cool pillow.
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Reviewed in the United States on March 30, 2026

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