SKU: 86359183497

Holley HP EFI ECU and Harness Kits 550-606

Sale price$1237.47 Regular price$1374.97
Save 10%

Pay in installments of $343.74 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Aug 4 - Aug 9

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

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

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.4 ★★★★★
Based on 30 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
S
Verified Purchase
SA
San Leandro, US
★★★★★ 5
Quick read, entertaining & informative
Format: Hardcover
This book can be enjoyed on several levels. It could be tongue-in-cheek or satire, but is also backed by facts and conjecture by one of the world’s greatest scientific thinkers. I think Dr. Tyson had fun writing it, and i certainly had fun reading it. And I learned a lot.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 29, 2026
P
Verified Purchase
Probably did
Waukegan, US
★★★★★ 5
Aliens: Know what to expect!
Format: Audiobook
This is a really fun review of Earth's obsession with alien life, what we have historically expected of aliens--and what they might expect of us. If you are a long-time listener of the author or a viewer of his YouTube show (Star Talk), you have probably heard much of what NDT has to say on this subject already--here and there as he picks his way thru the universe, but why not listen to him now again as he focuses his energies on just this alien subject? If you want an enjoyable read, it will be worth your time. If you're not a long-time listener of NDT... and you have any interest in aliens at all, then you DEFINITELY should give this book a go. It is full of thoughtful insights from a man who has devoted his life to the science and 'cultural impact' of the stars. I listened to the Audible version wherein NDT reads his own book aloud for you. His efforts really allow you to gain his insights... And his strong sense of humor--in equal doses. 5 Stars
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 12, 2026
T
Verified Purchase
Taylor
Cuba, US
★★★★★ 5
My son is actually motivated to do a workbook
Format: Paperback
My Kindergartener finished homeschool online early and we have been doing a page a day and he loves it and loves to earn a sticker after each day and put it on his chart. I love how engaging the workbook is and how it introduces some 1st grade concepts. Would highly recommend.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 23, 2026
A
Verified Purchase
Amazon Customer
Phoenix, US
★★★★★ 5
Excellent Kindergarten prep
Format: Paperback
My daughter is loving all of the learning exercises and has started feeling more confident heading in to Kindergarten.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 20, 2026
S
Verified Purchase
stephanie
Birmingham, US
★★★★★ 5
Excellent Summer Workbooks - Keeps Kids Engaged and Ready
Format: Paperback
These workbooks have been an absolute lifesaver for keeping my kids on track over the summer! I was looking for a resource that would help them retain what they learned and prepare for the next school year without feeling like a chore, and these deliver perfectly. What I particularly love is how well **organized they are by days**. This structure eliminates any guesswork and makes it incredibly easy to assign manageable chunks of work each day, which helps to **keep my kids consistently on track**. There's no overwhelm, just steady progress. The content is engaging, and it genuinely seems to reinforce key concepts in a fun way. We've had **absolutely no complaints** from the kids, which is a huge win for any summer learning material! I highly recommend these workbooks for any parent looking for a structured and effective way to bridge the academic gap during the summer break.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 28, 2025

recommand products