SKU: 50644243334

Holley HP EFI ECU and Harness Kits 550-603

Sale price$1282.47 Regular price$1424.97
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Ships within 48 hours · Estimated delivery Aug 2 - Aug 7

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Description

Holley HP EFI ECU and Harness Kits 550-603HP ECU AND HARNESS LS2 & LS7 Looking for a plug and play kit for your GM LS engine? The HP ECU allows you to accurately control the fuel and ignition of your engine plus much more. Got a stock LS engine? Simply download a base map and you're on your way. Got a turbocharged, nitrous fed LS engine on water meth? This HP EFI kit can control that too! Features: Simple Installation Plug and Play control of GM LS2 LS3 LS7 engines. Just plug the harness into

HP ECU AND HARNESS LS2 & LS7
Looking for a plug and play kit for your GM LS engine? The HP ECU allows you to accurately control the fuel and ignition of your engine plus much more. Got a stock LS engine? Simply download a base map and you're on your way. Got a turbocharged, nitrous fed LS engine on water/meth? This HP EFI kit can control that too!

Features:

  • Simple Installation - Plug and Play control of GM LS2/LS3/LS7 engines. Just plug the harness into your factory sensors, wire the power and grounds and you are ready to take complete control of your LS engine
  • More Functionality - Provides significantly more functionality than OEM or other competitive ECUs (boost control, nitrous control, water/meth injection, plus a host of additional inputs and outputs to control fans, pumps, relays etc.)
  • Easy To Use - Laptop programmable ECU includes a variety of base maps that will have you hitting the cruise or track in no time
  • Ideal For Everything - including stock 5.3L engine swaps or all out, 3,000+ horsepower race cars that need a simple and powerful ECU and harness solution
  • Industry Leading Self Tuning Fuel Strategy - means less time tuning and more time enjoying the power of your LS vehicle
  • Kit includes ECU, harness, communication cable, software, USCAR (EV6 Style) injector connectors, and Bosch wideband O2 sensor, designed to be used with GM LS2/LS3/LS7 engines with factory GM coils and a 58 tooth crank sensor
  • ECU is fully potted and can be mounted in the engine compartment or interior
  • Sealed automotive and marine grade connectors
  • 1-5 Bar MAP sensor capability
  • Optional plug and play hand-held programmer, 5.7" touch screen and digital gauges are available for ultimate control and vehicle monitoring
  • ECU is certified to ISO 8846, SAE J1171 & United States Coast Guard Requirements for Ignition Protection & Fire Resistance
  • For a full list of advanced features such as boost, nitrous, water/meth, individual cylinder control and more click the document icon under the product image! 

Application

  • Universal

Specs

Brand Holley EFI
Crank Reluctor 58x
Emission Code 4
Ignition Type GM LS 58x
Injector Connector USCAR (EV6)
Product Type HP EFI Kit
Part Number 550-603
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: 50644243334

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4.3 ★★★★★
Based on 18 reviews
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Product Reviews
J
Verified Purchase
Josh G
Waukegan, US
★★★★★ 5
Fit Perfect
Size: 2023-26 CRV 2.0L Hybrid
Fit perfectly on my 2023 CRV sport hyrbids. Use an 8mm socket for the engine filter cover.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 10, 2026
D
Verified Purchase
Donna Goodwin
Natrona Heights, US
★★★★★ 1
One filter works the other one doesn’t
Size: 2023-26 CRV 2.0L Hybrid
No, it does not work for the new 2025 Honda CRV only the cabin filter works the engine filter slips off and won’t allow you to fully put the cover back on on the new 2025 CRV Honda
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 3, 2026
J
Verified Purchase
Jami Regimbal
Louisville, US
★★★★★ 5
Perfect fit, good quality, great price
Size: 2023-26 CRV 2.0L Hybrid
Perfect size & was better quality than factory ones that came with the Honda. Honda’s cost to replace at service bay was close to $200!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 21, 2026
R
Verified Purchase
Rebecca LeBlanc
Whiting, US
★★★★★ 5
Better than the expensive ones!
Size: 22"+21"(Fit U & J Hook), Style: Fit For TOYOTA Tacoma 2014-2005 Solara 2003-2001
I bought these for my 2010 Toyota Tacoma and they fit perfectly! They are better than the ones that came on the truck. For the price, they are worth it all day long. They pop on in seconds and work very well. No noise. Very durable. Easy to install.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 5, 2026
A
Verified Purchase
Amazon Customer
Charlottesville, US
★★★★★ 5
Great price, work great!
Size: 12"(12-A)(Rear Wiper Blade), Style: Fit For TOYOTA RAV4 2024-2019,2012-2001,Highlander 2019-2001
Fit perfectly, easy install, they work great!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026

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