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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
4.1 ★★★★★
Based on 20 reviews
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Product Reviews
★★★★★ 4
Great bounce, loud squeak, smaller than expected
Great little ball with a high pitched squeak and a nice bounce. I recommend going with a bigger size than you think you need. They have the sizes in the discription and I thought the medium size would be perfect for my 45 lb dog but it was a little too small for her. Also my dog doesn’t tend to chew heavily, but I can imagine that some dogs might manage to break through the rubber without much effort because the rubber is soft enough to easily squeeze for the squeak.
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Reviewed in the United States on June 10, 2025
★★★★★ 5
Best Balls for aggressive chewers.
I have a bully and shepherd that tear up toys in 30 seconds. They got these for Xmas and it’s been over a week and they are still around in one piece. Very good quality. They have not been able to kill the squeaker.
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Reviewed in the United States on January 2, 2026
★★★★★ 5
Large tennis balls
Color: Mixed Color, Size: Large (Pack of 12)
These bald were great for a dog birthday party gift bag. The dogs loved them. They are a little larger than a regular tennis ball and great for larger dogs.
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Reviewed in the United States on May 30, 2026
★★★★★ 5
Great customer service
The squeakers broke within the first few minutes of my dog playing. But the customer service has been outstanding.
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Reviewed in the United States on January 17, 2026
★★★★★ 5
Awesome
Color: Mixed Color, Size: Small (Pack of 24)
Love this
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Reviewed in the United States on May 22, 2026