HP EFI ECU & Harness Kits - 550-601N
SKU: 34360476229

HP EFI ECU & Harness Kits - 550-601N

Sale price$1349.97 Regular price$1499.97
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Ships within 48 hours · Estimated delivery Jul 6 - Jul 11

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Description

HP EFI ECU & Harness Kits - 550-601NOverview: 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

Overview:

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.

Features:

  • 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/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 tuning precision unmatched in the industry

Application:

Year Make Model Submodel Engine Size
Universal

Specs:

Brand Holley EFI
Emission Code 3
Ignition Type Coil - (No Timing Control)
Ignition Type GM HEI Small Cap
Ignition Type Holley Dual Sync Distributor
Injector Connector Jetronic / Minitimer (Bosch)
Product Type HP EFI Kit
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: 34360476229

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Steve
Lowell, US
★★★★★ 5
Fit for 2021 Subaru Forester CVT
Size: 5 Quart, Style: 1 Pack
Works just fine in the 2021 Forester. Better value than subaru branded CVT Oil. Compatible with any subaru CVT.
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Reviewed in the United States on May 4, 2026
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Dwight Byrd
Omaha, US
★★★★★ 5
A much more affordable option for Subaru owners
Size: 5 Quart, Style: 1 Pack
When you're paying between $16 & $18+ per quart of Subaru brand CVTF 2 fluid this is a much more affordable option. If you look on the back of a Subaru branded CVTF 2 quart bottle you'll see the Idemitsu logo. Doing this job myself saved me over $1000 on what the dealership quoted me to change the valve body and drain and fill my CVT without skimping on anything.
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Reviewed in the United States on March 18, 2026
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neal
Fort Morgan, US
★★★★★ 5
Same fluid as the Subaru brand
Size: 5 Quart, Style: 1 Pack
This is the manufacturer that makes the Subaru cvt fluid. I used this for the drain and fill on a 2019 Subaru Forester. No problem using a hand pump to fill the transmission. Excellent product will use again to service a 2018 Subaru Crosstrek.
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Reviewed in the United States on April 22, 2026
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BGK^2
San Leandro, US
★★★★★ 5
2010 Subaru Outback CVT fluid 👍
Size: 5 Quart, Style: 1 Pack
2010 Subaru Outback CVT ... have been using this for several thousand miles instead of OEM fluid, and works just fine ... if your subie takes the "green" CVT fluid, this works excellent! I even used this after dropping the CVT valve body and replacing the lock up solenoid, so I had to replace with almost exactly 10 qts of fluid.
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Reviewed in the United States on May 20, 2026
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Henry
Battle Creek, US
★★★★★ 5
Worth it
Size: 5 Quart, Style: 1 Pack
Expensive but good.
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Reviewed in the United States on April 6, 2026

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