SKU: 39296231040

Holley Terminator X Engine Management Systems 550-905

Sale price$719.98 Regular price$799.98
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Ships within 48 hours · Estimated delivery Jul 13 - Jul 18

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Description

Holley Terminator X Engine Management Systems 550-905TERMINATOR X MPFI, LS2 LS3 & LATE TRUCK Take control of your LS engine with Terminator X! Don't settle for a junkyard ECU with a cumbersome tuning interface when you can have complete control of your engine, self learning fuel strategies and the proven, race winning technology of Holley EFI at a budget friendly price! Terminator X features real time fuel learn, high impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs

TERMINATOR X MPFI, LS2/LS3 & LATE TRUCK

Take control of your LS engine with Terminator X! Don't settle for a junkyard ECU with a cumbersome tuning interface when you can have complete control of your engine, self-learning fuel strategies and the proven, race-winning technology of Holley EFI at a budget-friendly price! Terminator X features real-time fuel learn, high impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs and outputs. The inputs and outputs are ideal for electric fans, boost control solenoids, progressive nitrous control, and much more. Terminator X comes fully loaded with base maps for common LS engine combinations to get you out of the garage and on the road/track fast. The 3.5" touch screen LCD handheld contains an easy to use calibration wizard as well as tuning and gauge display functions. Also included is Holley EFI's industry-leading, easy to use software suite that allows full laptop access for advanced users. Whether you are building a budget beater or a boosted race car, Terminator X has the features and technology you need at a price that won't break the bank!

Features:

  • Designed for GM LS Engines with 58x Crank, 4x Cam - and EV6 Injectors.
  • Real-Time fuel map learn, takes the guess work out of tuning your base fuel table.
  • High Impedance Injector Drivers will safely power most Stock LS injectors, and Holley EFI Injectors. Injector support chart provided in the instructions (Will not control Low Impedance Injectors)
  • All of the new Terminator X systems utilize the Bosch LSU 4.9 wideband to relay AFR information to the ECU for accurate reading and precise tuning control.
  • MAP Sensor vacuum hose adapters (1/8th – ¼ and 3/16ths)
  • 4 Inputs – 12v, Ground, 5v, and Frequency, for things such as additional pressure sensors, or activation triggers for nitrous activation, or a trans brake
  • 4 Outputs – Ground, PWM - , for accessories such as; fans, boost control, nitrous control, IAC Kit, and More
  • Boost Control – Boost vs Time, Boost vs Gear, Boost vs RPM, Boost vs Speed, Boost Safeties
  • Nitrous Control – Single Channel of Wet or Dry, Progressive or Non-Progressive, Rich/Lean Safeties, and target Closed Loop AFR
  • On-Board Diagnostic LEDS for: ECU Power – Engine Run – Wideband Status – TPS Calibration – Crank Signal –Cam Signal. Allow you to identify any Critical engine issues at a glance
  • Advanced Tables – 4x 1D Tables, 1x 1D per Gear Table, 4x 2D Tables, 1x 2D per Gear Table, can be used for any custom tables you can dream up, such as Flex Fuel Sensor Offset Table, or a custom fuel or oil pressure safety!adjustable through included 3.5” f
  • The included 3.5" Touchscreen Handheld contains a calibration wizard, that allows you to quickly build a base tune for any LS engine. Additionally the handheld provides internal data-logging and a fully customizable gauge display.
  • The compact ECU size allows you to mount it virtually anywhere. Remember, diagnostic LEDS must face up!
  • Plug and play compatible with more Holley EFI accessories such as; analog style gauges, shift lights, various modules, and coming soon, 12.3" digital dash support!
  • Free EFI Tuning Software for complete control of your Terminator X power plant
  • Includes: 58x/4x LS Engine Main Harness - EV6 Injector Harness - Terminator X ECU - ECU Main Power Harness - Bosch LSU 4.9 Wideband Oxygen Sensor - Input/Output Harness - and assorted vacuum adapters.

Specs

Brand Holley EFI
Crank Reluctor 58x
Emission Code 3
Ignition Type GM LS 58x
Injector Connector USCAR (EV6)
Product Type Terminator X LS MPFI
Terminator LS Options Fuel, Spark
Part Number 550-905
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: 39296231040

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Patrick
Fort Morgan, US
★★★★★ 5
Worth it if your dog destroys plush toys & likes to chew
Color: Cyan NylonFish
My dog is a very big chewer and destroyer of toys. This toy is perfect for her. It is durable and keeps her engaged chewing for a while. I have a 55lb dog, considered a large dog, and it’s a great size for her. She’s unable to break it apart. The ends do tend to get a little sharp after extended use
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Reviewed in the United States on February 14, 2026
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long islander
San Leandro, US
★★★★★ 5
My Boston loves this fish toy
Color: Cyan NylonFish
Very durable. It takes a couple of months of intense chewing to make holes in this toy. My Boston has incredible mouth strength so he destroys most toys in minutes unless they are rocks. I have replaced this fish 2 times in the last year. I keep an eye on the wear and replace it when he makes a hole in it. Worthwhile purchase but monitor the dogs chewing.
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Reviewed in the United States on April 23, 2026
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Jes
Draper, US
★★★★★ 5
Great sturdy toy
Color: Cyan NylonFish
Great toy. 1 yr old puppy LOVES it! However, not good for TILE FLOORS. It's so strong and sturdy but bangs all over the tile! Enough to crack tiles 😬
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Reviewed in the United States on September 27, 2025
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Elizabeth Alfaro
Los Angeles, US
★★★★★ 4
American Bully Trial - Honest Review
Color: Cyan NylonFish
I have never gotten a toy that lasted more than an hour when it comes to my baby girl. She is an aggressive chewer and loves anything that squeaks. This definitely helped to keep her entertained and use her teeth. I can confidently say that this toy may last a long time but she has already ripped a piece from it. I didn’t expect anything less since she always knows how to test new toys lol. I would definitely recommend though and will be getting more for her once this one is gone. Thank you!
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Reviewed in the United States on July 2, 2024
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keyjustice
Bozeman, US
★★★★★ 3
Hard, heavy, sharp
Color: Cyan NylonFish
This is very durable, but it is also very heavy (our dog likes to throw her toys) and after some chewing, the head and tail are very sharp
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Reviewed in the United States on April 25, 2026

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