SKU: 33339934358

Holley HP EFI ECU & Harness Kit (HO550-605)

Sale price$2633.85 Regular price$2926.50
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Description

Holley HP EFI ECU & Harness Kit (HO550-605)HO550 605 HP EFI ECU WITH UNTERMINATED Unterminated Universal Harness Part Number: HO550 605 Looking for a plug and play alternative for your stock or built late model factory 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

HO550-605 - HP EFI ECU WITH UNTERMINATED

Unterminated Universal Harness

Part Number: HO550-605

Looking for a plug and play alternative for your stock or built late model factory 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.
NEW V2 SOFTWARE FEATURES:
"Quick Start" ignition and fueling strategy for LS x Engines
Data Logger. Scalable axes, Smoothing, Multiple graph view ability, Pre-defined notes fields and many more
Strip Chart Real-Time Data Viewer
Integrated Boost Control - Boost vs Time, Boost vs Gear (Time or RPM), Boost vs RPM, Boost vs Speed, Launch control. Boost launch builder, Over-boost safeties, Boost scramble
Traction Control - Power reduction via timing, nitrous percentage or boost (Requires Davis Technologies Holley Module)
"Quick Start" fueling for all engines
Option for VE based fueling strategy
Fuel Map and Learn Function Smoothing
Configurable User Password Protection
Fully Configurable lap top Gauge Panel
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

Shipping Notes
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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]
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SKU: 33339934358

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4.6 ★★★★★
Based on 17 reviews
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Product Reviews
T
Verified Purchase
Tyler Woodall
Whiting, US
★★★★★ 1
Received broken unit
Size: Dog Rope Toy - M, Size: Dog Rope Toy - M
One of the two main strands of the toy are totally ripped apart and frayed before ever being used. Will fall apart very quickly, returning.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 8, 2026
A
Verified Purchase
Alma Farias
West Palm Beach, US
★★★★★ 5
Decent product. Fun for dogs
Size: Dog Rope Toy - M
My dogs loved this toy so much that they ripped it just after a month use. So durability may be lacking a bit but my dogs loved it. The price can be less since it doesn’t last that long, it’s lightweight so it’s easy to throw, and super fun for dogs.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on September 6, 2025
K
Verified Purchase
katherine reitnauer
Dallas, US
★★★★★ 1
Cheaply made
Size: Dog Rope Toy - M
I ordered this toy for my son's dog and in about 10 minutes or less it was falling apart I now have four pieces not a good product.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 15, 2026
J
Verified Purchase
John Thao
Lake Worth, US
★★★★★ 5
Fun tug toy that holds up well
Size: Dog Rope Toy - M
We got this rope tug toy for our dog and it’s been a hit. He loves playing tug of war and will happily drag this around the house looking for someone to play with. The rope is thick and feels like real cotton, not that super cheap stiff stuff. It has some give to it but still feels sturdy. So far it has held up well to lots of chewing and tugging. Our dog isn’t a hardcore destroyer, but he definitely tests his toys, and this one is still in one piece. It’s also a nice size, not tiny, so it works well for medium and bigger dogs, but a smaller dog could still enjoy it. Overall, it’s a simple toy that does what you want it to do. Keeps the dog busy, gives them something safe to chew on, and holds up better than most rope toys we’ve tried.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 3, 2026
T
Verified Purchase
T Lance
New York, US
★★★★★ 3
Red flag!!!
Size: Dog Rope Toy - M
Within an hour of giving this toy to my dog, she chewed off the plastic handle and the plastic ball. The worst part is that they came off in very small pieces, some like crumbles. This could have been a serious problem if I had not been watching her and able to take it away.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 12, 2026

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