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Description
Holley HP EFI ECU and Harness Kits 550-602HP ECU AND HARNESS LS1 & LS6 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! Stop reflashing your factory ECU every time you make a performance modification. Get Holley EFI today!
HP ECU AND HARNESS LS1 & LS6Looking 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! Stop re–flashing your factory ECU every time you make a performance modification. Get Holley EFI today!
Features:
- Simple Installation - Plug and Play control of GM LS1/LS6 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 and and Bosch wideband 02 sensor designed to be used with GM LS1/LS6 engines with factory GM coils and a 24 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" touchscreen 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
-
Univesal
Specs
| Brand | Holley EFI |
|---|---|
| Crank Reluctor | 24x |
| Emission Code | 4 |
| Ignition Type | GM LS 24x |
| Injector Connector | Jetronic / Minitimer (Bosch) |
| Product Type | HP EFI Kit |
| Part Number | 550-602 |
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
4.3 ★★★★★
Based on 17 reviews
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Product Reviews
★★★★★ 5
Actually, better than I expected!
Size: Medium, Unit Count: 4
These are better than what I was expecting based on the reviews. I do put them on carefully because someone said you can’t tear them so I’m careful putting them on, but they almost don’t feel like you’re wearing anything as long as you don’t put them too tight on your toes. I can put lotion on my feet and I know it has to soak in because there’s no place else for it to go like socks or my bed.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 20, 2026
★★★★★ 5
Moisturing
Size: Medium, Unit Count: 4
The silicone socks are nice, they help my dry heels. I will warn you don't walk with them I got up in the middle of the night and tore one pair.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 3, 2026
★★★★★ 3
So so...
Size: Medium, Unit Count: 2
They do what they advertised.
You can NOT walk in them you will stretch them and pop a hole in them.
You cannot sleep in them unless your going to wear larger cotton socks with them to keep them in place. They are easy to wash and dry which is nice. I will need to buy another pair. Great if your gonna watch a movie or binge TV in.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 7, 2026
★★★★★ 5
Great for dry feet or to help lock in moisturizer or medication
Size: Medium, Unit Count: 2, Size: Medium, Unit Count: 2
They’re stretchy and don’t feel goopy, I use them daily and they’re working great they keep my feet nice and hydrated and soft. I’ve been using them along with lotion to help hydrate my skin so they aren’t rough during the winter. They are comfy and if you must get up they’re grippy and don’t slip or slide they stay put. They’re super easy to put on and take off.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 25, 2026
★★★★★ 4
Comfort
Size: Medium, Unit Count: 4
Easy to put on.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 9, 2026
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