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USA
- USA
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- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 14 - Jul 19
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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:
- 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
4.0 ★★★★★
Based on 422 reviews
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Product Reviews
★★★★★ 4
amazing product, a little too pricey
it worked amazing while we were trying to swim in the ocean and snorkel in the ocean. The only downfall I have of this is the price is so much for such a little amount.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 15, 2025
★★★★★ 5
Great clean sunscreen
Great sunscreen, made of minerals instead of chemicals, holds nice in water when surfacing
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on September 6, 2025
★★★★★ 5
My go to brand
My go to brand. Other brands I have to reapply constantly and still have sunburn. I love this brand and the stick is even better for applying sunscreen. Very reliable without any mess!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 3, 2025
★★★★★ 1
Not fur Surfing or other Water Sports
I got this in a swag bag from a surfing contest. The stick is very dry...that's the only way I can explain how it feels. It certainly doesn't glide on like other face sticks. After one wave and ducking my face in the water, the product smeared off and ran into my eyes. My vision got blurry from that, and it was really hard to see the waves coming in. I won't be using this product ever again. I also looked at the EWG website, and this product was given a 6. For those new to EWG, that's not a good rating. You want like a 1 or 2.
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Reviewed in the United States on January 10, 2026
★★★★★ 5
Perfect for travel
Nice size and easy to apply. And no burns!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on September 15, 2024
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