SKU: 69643390480

Holley HP EFI ECU and Harness Kits 550-602

Sale price$1282.47 Regular price$1424.97
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Ships within 48 hours · Estimated delivery Sep 19 - Sep 24

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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 & 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 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:
  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: 69643390480

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4.3 ★★★★★
Based on 23 reviews
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C
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c.laff
West Palm Beach, US
★★★★★ 3
These are not sized correctly - beware
Color: Blue-ice Plus, Size: King(Pack of 2), Color: Blue-ice Plus, Size: King(Pack of 2)
Edit: I was going to return these pillows but the seller contacted me and offered a full refund due to the size issue without having to send the pillows back. I am happy with this and happy to keep them on a spare queen size bed as they really are nice pillows. Just the wrong size. pros: they are a nice pillow and the cooling feature is really great, and you can adjust to your liking cons: absolutely wrong size. Ordered King, tag says king, all measurements on listing and tag say 20x36, in reality they are more like 20x30. Definitely Queen pillows being sold as King. I did not see any reviews at first about size issues but after I got these and did a search it does look like others have had the same problem. A shame, would have given them a great review if they were the correct size
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 23, 2026
L
Verified Purchase
Leah Ann Dillin
Louisville, US
★★★★★ 5
Cool and comfy
Color: Blue-ice Plus, Size: King(Pack of 1)
Great pillow. Keeps you cool.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026
R
Verified Purchase
Rene
Natrona Heights, US
★★★★★ 5
Really Good Cooling Pillows for Sleeping
Color: Blue-ice Plus, Size: Queen(Pack of 2), Color: Blue-ice Plus, Size: Queen(Pack of 2)
These cooling pillows are very soft and provide excellent support for your head and neck. They are adjustable by taking our the stuffing if you need them to be more flat or less firm. The look great and comes in a pack of two which is a great value. During use, I did notice they have great shape retention and it does not take them long to return to their fluffy full shape. I am a hot sleeper and these do keep your head cool - just be aware using a pillow cover does reduce the cool ability but this allows you to adjust for weather like during winters to add a pillow case for extra warmth. Very happy with this purchase and got a second set to replace my old pillows.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 28, 2026
R
Verified Purchase
ryguy
Lexington, US
★★★★★ 5
Soft and smooth cover
Color: Grey, Size: Body(20"X 54")
This is a nice pillow cover overall. The fabric feels good and it's comfortable to sleep on, especially compared to a more basic cotton cover. It is maybe a little thinner than I expected, so if you want something thick and heavy this probably isn't that. But for a soft smooth cover that fits and feels decent, I think it's worth it. No major complaints from me after using it.
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Reviewed in the United States on May 16, 2026
K
Verified Purchase
Kindle Customer
San Leandro, US
★★★★★ 5
These are the ones you want
Color: Grey, Size: Body(20"X 54")
May need to iron them out when wash/dried but my old ones still look new- soft, cooling, smooth, color is still great. Not itchy or cheap feeling. Buying a new set for family.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 15, 2026

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