SKU: 5404454097

Holley HP EFI ECU and Harness Kits 550-606

Sale price$1237.47 Regular price$1374.97
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  • USA
  • CAN

Ships within 48 hours · Estimated delivery Sep 8 - Sep 13

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Description

Holley HP EFI ECU and Harness Kits 550-606FORD MPFI HP ECU AND HARNESS KIT 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

FORD MPFI HP ECU AND HARNESS KIT

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 for Water/Meth tu

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 550-606
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: 5404454097

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4.1 ★★★★★
Based on 19 reviews
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Marcia Weldon
Port Orchard, US
★★★★★ 5
More than expected
Color: Cyano Pink Spicule
Love, love and recommended to friends. Leaves my skin feeling and looking great. At 69 I don't expect miracles but can definitely see an improvement in texture, glow and line minimizing. I'm hooked and will never be without!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 5, 2026
E
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Eric S.
Birmingham, US
★★★★★ 5
Micro-needling effect!
Color: Cyano Pink Spicule
Love how you can feel the micro-needling effect. I use this is my first application after toning and follow up with my serum and moisturizing routine. I do believe it gives my face a plump feeling, especially after gua sha. Will continue to use in my daily!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 21, 2026
M
Verified Purchase
Michelle B. Govertsen
Lexington, US
★★★★★ 4
Helps my moisturizer absorb better
Color: Cyano Pink Spicule
I’m not quite sure if the product is fully working the way it is supposed to but I do like that when I use this and the apply moisturizer, it absorbs into my skin better and leaves my skin smoother and a lot less greasy. It’s easy to throw in my travel bag because of the size and you really only just need a little for each use so it goes a long way got the cost.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 31, 2026
R
Verified Purchase
Raschell
Lexington, US
★★★★★ 5
Amazing!
Color: Cyano Pink Spicule
This makes my skin feel so smooth. The appearance of my skin also is starting to look a lot better/younger. I've been using it for a week and a half already seeing changes.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 11, 2026
H
Verified Purchase
Holly K.
Phoenix, US
★★★★★ 3
Brightens, doesn't firm
Color: Cyano Pink Spicule
I've been using this for about a month now, every night on my face and neck, hoping to reduce the appearance of wrinkles and tighten some of my skin in that area that seems to be losing elasticity. On my neck, I've honestly noticed no real difference in 4 weeks of continued, consistent daily use. The skin on my face does seem brighter and somewhat less textured than before, but I haven't noticed any change in the issues I was hoping this would resolve, based on the claims and how it was marketed. So... not a bad addition to my skincare, but not the solution I was looking for. Some have expressed concerns about it tingling or stinging... You can feel something when you apply it, it's almost like the feeling of static electricity, but it's very mild. I wouldn't let that stop you from giving it a try if you were concerned about it. It didn't cause my sensitive skin any breakouts or redness (although I was applying it at night before bed, so perhaps any redness was calmed overnight). I'm going to go ahead and finish the bottle, but based on these results, I probably won't repurchase.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 3, 2026

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