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
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SKU: 44499070246

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Amazon Customer
Natrona Heights, US
★★★★★ 5
Beautiful, Super Thin, Fast
Capacity: 16GB Unified Memory | 512GB SSD Storage, Color: Silver, Set: Without AppleCare+
It’s beautiful, super thin, very fast, and the screen size reminds me of the large iPad Pro. I have to get used to not touching the screen like you do with an iPad. You must use a mouse or your finger. Also programs work differently than apps. Make sure you are ready for that if you are only used to using an iPad.
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Reviewed in the United States on May 27, 2026
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Nick
Dallas, US
★★★★★ 5
Awesome
Capacity: 16GB Unified Memory | 512GB SSD Storage, Color: Midnight, Set: Without AppleCare+
This computer is great, it's fast, reliable, and it has a great amount of screen real estate. It's great for people who have trouble reading or people who have to multitask.
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Reviewed in the United States on May 5, 2026
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Amazon Customer
Whiting, US
★★★★★ 5
Life changing little screen
Size: 15.6" 1080P, Size: 15.6" 1080P
I was losing my mind trying to work from home off a single laptop screen. Secondary displays were not connecting to my computer outside of the office, IT could not figure out the issue so I was doomed to single screen anytime I worked from home. A co-worker suggested I take a look at this style of screen. I had my doubts that it would work with my lap top, and lo and behold I am back in action with a dual display. It comes with an HDMI cord option and a USB-C cord option (you do not need to buy separate cords, they are included). I used the USB-C as it also acts as a power cord to power the display. It took two seconds to hook up, and with one setting change on my lap top the display successfully extended (does not just duplicate your display, it will allow display extension as well). The image quality is more than sufficient for work (no opinion on PC gaming) and settings such as brightness were easy to adjust. It's the perfect size for use with my lap top screen, and they had plenty of additional size options. The built in stand allows two screen angles, and acts as a cover when not in use. For the price this thing is absolutely clutch, don't waste money on expensive displays - you can use this with any USB-C capable device so it can travel with you for work or fun. I will be interested to see if it has longevity, but for now I'd give this thing 10 stars if I could.
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Reviewed in the United States on February 10, 2026
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Traveling Nurse
Lexington, US
★★★★★ 5
Great product for a great price
Size: 15.6" 1080P
I REALLY like this. I need 2 screens to do my job efficiently and have struggled lately when traveling. Splurged on this for myself and was really impressed. It’s nice and lightweight but feels sturdy. The image quality is good. The set up could not be easier. This is a game changer for me.
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Reviewed in the United States on May 23, 2026
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AH
San Leandro, US
★★★★★ 5
Works pretty well for a cheap monitor
Size: 15.6" 1080P
I work remote and travel, so I miss my multi monitor setup. Not anymore. I took this on a trip with me and it was great. The stand folded over to not take up too much desk space, the cables wear just long enough, another 6” would have been great but they worked. Quality of the screen is plenty good enough for office work, I have no gaming or artwork experience with it though. If you need an inexpensive 2nd monitor , this works great for on the go or even for a regular desk.
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Reviewed in the United States on May 3, 2026

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