Shipping Estimate
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- USA
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- USA
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Ships within 48 hours · Estimated delivery Jul 13 - Jul 18
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Description
Holley HP EFI ECU and Harness Kits 550-602NHP ECU AND HARNESS, LS1 6, NTK 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, LS1/6, NTK
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 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 NTK wideband 02 sensor designed to be used with GM LS1/LS6 engines with factory GM coils and a 24 tooth crank sensor
- The NTK Oxygen Sensor is recommended when using leaded or methanol fuels, high exhaust temperatures and forced induction applications or for highest precision feedback
- 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
- Universal
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 | 550-602N |
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
4.6 ★★★★★
Based on 754 reviews
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Product Reviews
★★★★★ 4
Runs small
Size: 8.5, Color: Sandstorm
This shoe is super cute and comfy. I usually wear an 8 or an 8½. I ordered the 8½, but it was too small, so I had to send it back. I reordered a 9, and it fit perfectly.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 20, 2025
★★★★★ 5
Love love these
Size: 7, Color: Black
Totally love these.
I found them to run a bit short. I ordered a 6 1/2 (my normal size) - had to return them for a 7.
But I love them.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 15, 2026
★★★★★ 3
Narrow at toes
Size: 8, Color: Smoke Grey
Cute but very narrow at the toe opening. My feet are a little wide their so they are not very comfortable
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 24, 2026
★★★★★ 5
Love these
Size: 6, Color: Black
Love these shoes. Very nice quality. Lots of compliments every time I wear them. I have two pairs - one black and the other light tan. I highly recommend.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 27, 2026
★★★★★ 5
Nice Bags Lots of Colors
Color: Black, Size: Standard 15.6 Inch
This was a great carry on bag for me. The size is perfect and has lots of pockets. The material is very nice and durable and I got black but it is still a nice color black with many other colors to
Choose from. I brought it to London and was very happy with its functionality. It does get a little heavy when lots of things are in it but I am not used to wearing a backpack. It does have a loop to slide onto your carrying on luggage handle as well.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 26, 2026
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