Holley HP EFI ECU & Harness Kit (HO550-601)
SKU: 44499070246

Holley HP EFI ECU & Harness Kit (HO550-601)

Sale price$2636.55 Regular price$2929.50
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Description

Holley HP EFI ECU & Harness Kit (HO550-601)HO550 601 HP EFI ECU WITH HARNESS Suit GM TPI & Holley Stealth Ram Part Number: HO550 601 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

HO550-601 - HP EFI ECU WITH HARNESS

Suit GM TPI & Holley Stealth Ram

Part Number: HO550-601

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/Meth

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: 44499070246

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4.4 ★★★★★
Based on 1569 reviews
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Anthony Ginnetti
New York, US
★★★★★ 5
Great product! Durable, chewable, awesomeness!
Color: Grilled color, Color: Grilled color
Very well made and durable. My dog hasn't left them alone since i opened them. Hes been at it for about 45 minutes straight now! Lol. He's an avid chewer. He will chew thru and fabric or cloth toys in less then a day. But these are what he really likes because they take time to chew apart. The shapes, are great, because one he props up with his paws and chews and it seems like it's easy to grip for him. Thru are hard so if you have hard floors it can get a bit noisy when he drops them. Over all this is a great product. Safe, chewable, long lasting, fun shape looks real to him (i think lol), Me and my dog Lucky are both happy with his new toys!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 27, 2026
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Verified Purchase
Jackster
Port Orchard, US
★★★★★ 5
Recommend for very heavy chewers
Color: Grilled color
My aggressive chewers love these! It’s been a few weeks and still in one piece and man they chew them for hours on end.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 26, 2026
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Nicholas Kiefer
Massapequa, US
★★★★★ 5
Amazingly great product!
Color: Grilled color
I’m not just saying this, ok, this is not hyperbole: this is THE best nylon bone for chewing that I have ever purchased. And you get TWO of them for relatively less expensive than most chew toys give you one! I have 2 golden retrievers, and if you know goldens, you know that they are some of the most relentless and powerful chewers around. So I can’t give them almost any toy other than rubber stuff or it will be destroyed in a period of time that doesn’t make it worth it. One of them even figured out how to destroy a supposedly indestructible toy made out of kevlar! She was able to get into it through the seam, which is not kevlar ha ha. Anyway, I digress; I never even considered nylon chews because they suck! Usually. Usually my dogs in the past have lost interest with them in less than a day. I took a chance on these mainly because of the novel shapes, the fact that they give you two, and the low price. Both my goldens LOVE these! Not just for one day, but going on weeks now! I don’t know if it’s the flavor or what, but I will see them gnawing on one of them at some point every day. And they CAN’T destroy them (I knew nylon was good for that, but it was the “who cares” attitude of my previous dogs toward nylon that kept me away). Both the “ribs” and “steak” (quite clever) are a bit worn on the edges now, but they look like they will be around for years. You can’t go wrong with this product (unless for some reason your dog does not like the flavor, but the flavor seems to be what draws my dogs to them). I highly recommend this (these) as the most cost-effective chew toy I’ve ever purchased.
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Reviewed in the United States on November 1, 2025
S
Verified Purchase
Sue Roob
New York, US
★★★★★ 4
Great for larger dogs
Color: Grilled color
I think they were heavy duty and durable, but they were too heavy for my dog. The seller was excellent though!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 31, 2026
R
Verified Purchase
Rodney
Charlottesville, US
★★★★★ 5
Dog chew toys
Color: Grilled color
Smaller than expected but dogs liked it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 28, 2026

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