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- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 14 - Jul 19
For Your Every Summer RSVP, with Code: SUMMER15
Description
Holley HP EFI ECU and Harness Kits 550-606FORD MPFI HP ECU AND HARNESS KIT Looking for a alternative for your stock or built late model factory FORD EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along
FORD MPFI HP ECU AND HARNESS KIT
Looking for a alternative for your stock or built late model factory FORD EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost or water meth.
Features:
- Optional 5.7” full-color touchscreen LCD allows easy on-the-fly tuning,data-logging or can be used as an easy to see graphical gauge panel
- Eight sequentially driven 8:2 peak and hold injector drivers, capable of driving up to 16 low or high impedance injectors as a standard feature. Multiple staged injector strategies
- Eight channel Distributorless Ignition (DIS)outputs capable of directly driving “Smart” ignition coils or Holley DIS coils. Will drive 2 wire coils with the addition of PN 554-112 high current coil driver module
- Plug and Play control of factory GM 24x and 58x LSx engines
- Integrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors
- Internal data-logging standard with a huge 2GB of memory
- 4 Stage progressive nitrous control
- Turbo boost control
- Integrated water/methanol injection control
- Self-tuning fuel table strategy greatly simplifies tuning process
- Individual cylinder fuel and spark control allows you to unlock your engine’s potential
- Works with 4, 6, 8 cylinder engines
- Unique lb/hr based fueling strategy greatly simplifies and commonizes tuning
- Advanced idle, closed loop, and enrichment strategies allow for very stable operation
- ECU is fully potted and can be mounted in the engine compartment or interior
- Sealed automotive and marine grade connectors
- Allows for use of common OEM sensors as well as customer sensor calibration input
- Ignition Plug and Play with GM 24x and 58x LSx engines, GM HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. New Plug and Play applications in process. Custom settings can be configured to allow many other applications
- 1-5 Bar MAP sensor capability
- Two channel knock control sensor Inputs for both one or two wire knock sensors
- Dedicated fuel and oil pressure inputs
- Controls both stepper and PWM Idle Air Control (IAC) motors
- Speed density, Alpha-N, or combination fueling strategies
- 4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use
- 4 Stage nitrous oxide control
- Fully featured nitrous control eliminates the need for a separate nitrous controller device
- Can be configured “Wet” or “Dry” with closed loop feedback
- Progressive control based on time, RPM, or boost, requires part # 554-111
- Lean or rich safety cutoff
- Full timing retard/control configurability per stage based on RPM or time
- Integrated Water/Methanol injection control
- Uses Holley Water/Meth solenoids specially designed and calibrated for use with this EFI system to allow the user to enter Water/Meth flow as a percentage of fuel injector flow for Water/Meth tu
Application
-
Universal
Specs
| Brand | Holley EFI |
|---|---|
| Emission Code | 3 |
| Ignition Type | Coil - (No Timing Control) |
| Ford TFI | |
| Holley Dual Sync Distributor | |
| Injector Connector | Jetronic / Minitimer (Bosch) |
| Product Type | HP EFI Kit |
| Part Number | 550-606 |
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 2206 reviews
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Product Reviews
★★★★★ 5
AAA
Color: Anthracite
Calidad insuperable, 10/10
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Reviewed in the United States on May 1, 2023
★★★★★ 5
Great, comfortable jeans.
Special Size: Low Stretch, Size: 34W x 30L, Color: Dark Midnight Wash
Great jeans! They're relaxed, but not loose or super baggy, so they still look great. I got the dark wash and you can wear them as dressy jeans or just casual out and about. I have bigger thighs and the 34x30 fits perfectly with room still to spare and not constricting at all. Whether it's walking around a lot, or sitting down for hours, it's very comfortable.
We'll see how long they last but I washed them once already and are holding up.
The length is good as well. When I don't have shoes I probably need a belt or could've ordered 29 length, but they're fine when I have shoes on. They don't slip down at all.
Especially for the price compared to Levi's or others that cost 40, 50, or even $60 this is a great deal.
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Reviewed in the United States on November 12, 2025
★★★★★ 5
If you’re on the fence read this
Special Size: Low Stretch, Size: 40W x 30L, Color: Iced Light Wash, Special Size: Low Stretch, Size: 40W x 30L, Color: Iced Light Wash
In all honesty, I was skeptical about ordering jeans from Amazon. I’ve always bought my jeans in stores, but I figured I’d give it a shot. I ordered these jeans for an upcoming outdoor wedding because I wanted something lighter and thinner. They showed up today, and I threw them on. They fit great, feel good and comfortable, and they don’t look cheap. I’ll mainly be using these for outings, so I can’t really attest to the durability as far as working in them, but I’d still suggest them. For reference, I’m 5’8” and 230 lbs with a husky build—kind of fit, kind of fat.
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Reviewed in the United States on March 12, 2026
★★★★★ 5
These are great jeans
Special Size: Low Stretch, Size: 34W x 28L, Color: Grey Wash
These are great jeans for the price especially
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Reviewed in the United States on May 3, 2026
★★★★★ 4
Run big
Special Size: Rigid, Size: 40W x 30L, Color: Medium Blue Vintage
Bought for my husband and very loose in butt and legs and he's normally that size so maybe buy a size down
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Reviewed in the United States on April 22, 2026