SKU: 62968518913

Holley HP EFI ECU and Harness Kits 550-606N

Sale price$1349.97 Regular price$1499.97
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  • USA
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Ships within 48 hours · Estimated delivery Aug 15 - Aug 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: 62968518913

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4.1 ★★★★★
Based on 11 reviews
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Savannah Thomas
Carnegie, US
★★★★★ 3
It’s pretty good!
Size: Queen (1 Count), Color: Crescent White
It’s okay ig… comes with a TON of stuffing but is removable and it’s got 2 different sides that feel different. One is cooling and one is comfort. It overall good pillow, but nothing special about it fr. Good quality though.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 8, 2026
N
Verified Purchase
nicole
Carnegie, US
★★★★★ 5
Love it
Size: Queen (2 Count), Color: Crescent White
So comfortable like a cloud i sleep great no aches in my shoulders or neck when I wake up
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 29, 2026
M
Verified Purchase
Mopardodgegirl
Massapequa, US
★★★★★ 5
It works! Quality pillow.
Size: Standard (1 Count), Color: Original White (Cooling)
This does actually provide a cooling effect, and it's very comfortable! The accompanying literature is helpful too. I believe this to be a quality pillow for the price.
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Reviewed in the United States on June 2, 2026
J
Verified Purchase
jin
Natrona Heights, US
★★★★★ 5
Most comfortable pillow I’ve ever slept on
Size: Queen (1 Count), Color: Crescent White(cooling)
This is the most comfortable pillow I have ever slept on. It doesn't mash down like other pillows. Cradles my neck perfectly plus it’s cool. I broke my neck a couple of years ago and this pillow feels very good and comfortable. Definitely recommend to everyone. Ive used it since May and it’s retained its shape.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 6, 2026
A
Verified Purchase
AreTrue
San Leandro, US
★★★★★ 4
Smell
Size: Queen (2 Count), Color: Original White (Cooling)
The fact that there are not more comments on the smell of these pillows has me worried about some of yall. Listen, I LOVE the weight, and the firmness, it’s perfect for that. However, these pillows are RANK. They have a very strong mildew-ish smell that lingers. I took the outer cover off and washed it and let the pillow air out for a few days, the smell is still very strong when you press your face against it, which one does because it is in fact designed for that purpose. It smells so bad. It’s nauseating. I can smell it through two pillowcases and blanket that I threw on top of them hoping an extra layer would trap the smell. I’ll bake them in the Texas sun tomorrow and hope that helps, because otherwise these are the perfect pillows for someone who wants to feel like they are hugging a torso but can’t stand the sound/feel of someone else breathing. I don’t know…4 stars, if the smell goes away I’ll come back. Update: many many days later. Either they don’t really smell anymore or I got use to it. They’ve held their firmness and shape well. I like them.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 9, 2026

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