Pay in installments of $387.49 with
,
and
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Aug 12 - Aug 17
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
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 15 reviews
Sort
Product Reviews
★★★★★ 4
nice watch but expect what you pay for.
Color: A Gold, Color: A Gold
Pretty solid watch decent size face i prefer large face watches even with my small wrist. Its pretty good at staying synchronized. The case is pretty solid but closer inspection makes it look cheap, i still love though and it does get a lot of looks. The band is my really only big complaint it feels chintsy and cheap, the clasp spring fellout once but very simple to re-insert and if you have small wrist like me its definite resize. Other than that for the price its a cool mechanical watch.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 16, 2015
★★★★★ 3
Nah....it's OK
Color: A Gold
Product does looks amazing and the manufacturer put a lot of time on designing this affordable watch, i'm using it in a daily basis and still looks like the first day.
Pros: Affordable, great looking, right size
Cons: Lot of condensation, you can see it trough the glass
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 15, 2016
★★★★★ 5
Amazing brand
Color: Silver Gold
Love these watches so much.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 13, 2026
★★★★★ 5
good for big wrists
my wrist is almost 9 inches so some choices are too small. plus I like a slightly loose fit rather than snug. it's beautiful just like the pictures. happy with it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 10, 2022
★★★★★ 5
Husband loved the watch
Husband loved it! Very nice and heavy
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 29, 2026
recommand products
Lenny Kravitz - Let Love Rule - 2LP
169.00
Various Artists - Rock' N' Paris - LP
120.00
Various Artists - Music Tribute Tarantino - The Very Best Songs From Quentin Tarantino's Films - 2LP
120.00
Melange Wool Slim Cap - Navy
110.00
Captain America Trilogy 3-Movie Collection Blu-Ray 4K Ultra HD
174.50