SKU: 86359183497

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 Jul 10 - Jul 15

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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: 86359183497

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jesus arcila
Pawtucket, US
★★★★★ 5
Sleep like a baby
Bringing a new puppy home can be rough on both of you, but this little heartbeat soother made such a difference. The first few nights my pup was whining constantly, but once I tucked this into his bed he settled down so much faster. The heartbeat sound is realistic and soothing — not annoying or too loud. It’s compact, easy to turn on, and the design is simple and clean. Great for separation anxiety too, not just new puppies. Totally worth it for the peace of mind alone!
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Reviewed in the United States on May 22, 2026
P
Verified Purchase
Pat S.
Charlottesville, US
★★★★★ 5
Works great. Easy to install
Great! Fits perfectly inside of stuffed dog. Great heartbeat sound.
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Reviewed in the United States on May 20, 2026
J
Verified Purchase
Jessica Frigo-Smith
Phoenix, US
★★★★★ 4
Heartbeat machine
Not what I was expecting. Pretty small and you can't really hear it. I was hoping to put it up on a shelf for my dogs when I leave. But, they'll never hear it. I'm sure I can use it for something else. Just not what I was hoping to unfortunately
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Reviewed in the United States on January 16, 2026
R
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Ruthie
Belleville, US
★★★★★ 5
Great replacement heart for bear toy
Many years ago I bought a Heart to Heart Bear (1980s)--with a heartbeat. After several years the heart stopped working, but I kept the bear--thinking that some day I could fix it. Last Saturday I replaced the original heart with this heartbeat toy and now she works great! The heart is not too loud and the fact that I can start and end it without opening the bear is great. I am going to buy another one as back-up just in case this one stops working. Thank you.
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Reviewed in the United States on November 13, 2024
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Kelammo
Omaha, US
★★★★★ 1
Can’t get it open.
We CANNOT get the screw out to put in batteries! Can you send me another?
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Reviewed in the United States on November 15, 2025

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