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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
4.4 ★★★★★
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Product Reviews
★★★★★ 5
BEST lip sunscreen I have ever used
Size: Pack of 1
best lip sunscreen I have ever used. Currently in/on Curaçao and no burn! Was out all day yesterday in the sun and this stick was only reapplied 3 times between 8am and 4pm. Reef safe too, that is important to me!
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Reviewed in the United States on April 15, 2026
★★★★★ 5
Great sunscreen
Size: Pack of 1
Love it! Not greasy, rubs in well, & doesn't smell. Doesn't leave the typical white sheen if you blend in well. Great to add foundation over. Ingredients are less chemicaly than other products.
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Reviewed in the United States on March 15, 2026
★★★★★ 5
Good stuff
Size: Pack of 1
Very nice to use
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 28, 2026
★★★★★ 5
Good protection, water resistant
Size: Pack of 1
I love their products. This is no exception. Used it recently in the Caribbean and Florida. Did a great job of protecting my lips and also seemed to have some resistance to washing off when I was swimming or snorkeling.
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Reviewed in the United States on March 5, 2026
★★★★★ 5
This lip balm has worked well for me overall
Size: Pack of 1
This lip balm has worked well for me overall. It does what I want from an SPF lip balm and I have not had any major complaints using it. The only minor downside is that it is a little soft, so when you first start using a tube you may notice a few small chunks on your lips. That has not been a big enough issue to bother me much, but it is worth mentioning. Aside from that, it has been a good product and I would keep using it.
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Reviewed in the United States on March 10, 2026