SKU: 39366981107

Holley Sniper EFI XFLow 4BBL Self Tuning System - Black Ceramic (HO550-541)

Sale price$1750.95 Regular price$1945.50
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Description

Holley Sniper EFI XFLow 4BBL Self Tuning System - Black Ceramic (HO550-541)HO550 541 HOLLEY SNIPER EFI BLACK 800HP 900 cfm 4 Injector Throttle Body, 800 HP N A Part Number: HO550 541 Introducing Sniper EFI XFlow! Are you building a naturally aspirated engine up to 800 Horsepower? Looking to convert your blow through carbureted turbo engine to EFI? Look no further! The Sniper EFI XFlow from Holley features 4, 120LB HR Fuel Injectors and flows 900CFM allowing it safely supporting up to 800 HP on Naturally Aspirated engines.

HO550-541 - HOLLEY SNIPER EFI BLACK 800HP

900 cfm 4 Injector Throttle Body, 800 HP N/A

Part Number: HO550-541

Introducing Sniper EFI XFlow! Are you building a naturally aspirated engine up to 800 Horsepower? Looking to convert your blow through carbureted turbo engine to EFI? Look no further! The Sniper EFI XFlow from Holley features 4, 120LB/HR Fuel Injectors and flows 900CFM allowing it safely supporting up to 800 HP on Naturally Aspirated engines. The XFlow comes with an internal 2.5bar MAP sensor that will safely work on boosted applications up to 21.5 psi. For applications making more than 21.5 psi, and has three additional 0-5v Sensor Inputs which can be used for an external MAP Sensor, or Dome Pressure for boost control, as well as oil pressure and fuel pressure. An External Fuel Pressure regulator is required; we recommend part number 12-848 for N/A applications.
Features:
Supports up to 800HP N/A with 4 120 Lb/Hr Injectors
Flows 900CFM, making it perfect for high rpm N/A engine combinations
Compatibl e with Draw through or Blow through forced induction applications
2.5Bar MAP Sensor
Integrated ignition timing control
Built in Single stage progressive nitrous control
User friendly Boost Control with handheld adjustability
Programm able Target Air Fuel Ratios per Boost level
Advanced boost control available via free Sniper EFI tuning software, including Boost vs RPM and Boost vs Time.
Three Programmable 0-5V Sensor Inputs for Oil/Fuel/Dome or Nitrous Pressure Sensors
Six Programmable Ground Outputs
One +5v Reference Output - +5V Power Supply for 0-5v Sensors
One Sensor Ground - Ground supply for 0-5v Sensors
Dual Pattern bolt on carburetor replacement, designed to fit 4150 Flange & Spread Bore manifolds - (Spread Bore Sealing Plate Part #9006 is recommended)
Throttle body mounted ECU - no extra boxes to mount
Only 4 Wiring Connections Required! (Battery +, Battery - , Switched Ignition & RPM)
Requires an external fuel pressure regulator: P/N 12-848 up to 800 HP
High Resolution Full Color Touchscreen for Initial Setup, Tuning, and Gauge Displays
Simple Calibration Wizard (Answer a few questions about your engine and it creates the base map, then starts tuning on its own!) - NO laptop required!
Self-tuning ECU means you don't have to be a computer/tuning wiz to have EFI!
The included Genuine Bosch LSU 4.9 Wideband Oxygen Sensor provides realtime Fuel Map Learn!
OEM Style TPS/IAC and Fuel Pressure regulator, for years of dependable service.
Included 2.5" clamp-on oxygen sensor kit ensures a leak free oxygen sensor installation, with Stainless Steel T-Bolt clamps and a Stainless Steel (Weldable) oxygen sensor flange

Shipping Notes
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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: 39366981107

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4.6 ★★★★★
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faith
Grantham, US
★★★★★ 5
Great Dog Chew!
My American Pitbull who is 10 months old is an aggressive chewer. He loves this Tikaton bacon scented dog chew. My picture reflects the part he loves the most-the center. It’s his favorite chew & has been chewing on it nonstop & there’s little sign of true wear & tear. He licks the outer portion & really focuses on chewing the center. I like how it’s a non-toxic nylon. The box clearly gives a heads up that this could be a chocking hazard so I do watch him when he’s chewing. He’s 60lbs. & I did get him a large so it’s not too small for him. I don’t foresee him choking on it but I’m cautious. Despite his aggressive chewing there has been zero sign of any piece tearing off. I like how it’s designed so he chews from the side rather than from the top or bottom. I did take a picture, for your reference, which I hope is helpful, of what the box reads in regards to the chew in general. Possibly this will determine if you feel this is right for your dog. I feel it’s a quality chew & it’s worth what I paid. I do recommend!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 4, 2023
M
Verified Purchase
Marie Davis
Chelsea, US
★★★★★ 1
Dogs would not even put in their mouth!
Flavor Name: Beef, Size: Large
Toy is rock hard. Have seen toys like that before, but the smell is disgusting. I have 5 dogs, and while this was purchased for one in particular, none of the dogs would chew on it. Only one put it in his mouth, and then immediately spit it out. My dogs are not picky or finicky but none would have anything to do with it. Total waste of money.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 7, 2026
K
Verified Purchase
Klara Gengler
Houston, US
★★★★★ 5
Last a while. Will be buying more toys soon.
Color: Consuela the Cactus - Large, Size: Large Dog
Best dog toy I have ever bought. I have three dogs, two at the time I bought this toy. It took them over a year to break through the first layer. The flower comes off first so be careful your dog doesn't swallow it. It still has the second layer so it still looks like a cactus. No stuffing to clean up when they tear into it, which makes it far less messy than other toys. One of my dogs is obsessed with fetch so I use it like a ball inside. The oval shape makes it hard to ensure when it bounces that it will bounce straight. It's bounced into walls and other stuff that I wasn't intending it to hit. Not much of a squeak so I can let them play with it for hours and I don't get annoyed with the noise. Great toy that lasts a while.
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Reviewed in the United States on September 25, 2025
C
Verified Purchase
Cassie
Charlottesville, US
★★★★★ 5
Nice Value
Color: Consuela the Cactus - Large, Size: Large Dog
Very cute! Its soft and feels like it is well made. It is a heavier toy and a tougher one. Not a plush toy. I will order again for our older dogs. Nice value for sure!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 11, 2026
B
Verified Purchase
Blakely McAllister
Battle Creek, US
★★★★★ 5
Great toy for our best boys!
Color: Consuela the Cactus - Large, Size: Large Dog
You can never go wrong with BarkBox toys and this was no exception. Our dogs like toys that have squeakers and that they can tear into. This style of toy fits the bill. The design is cute as well. I’ve had this in the house for months and, while it’s definitely seen better days, it’s still intact and they haven’t gotten to the inner layer. (Not for want of trying.) The perfect type of toy for our fur babies.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 10, 2026

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