SKU: 11379111417

Holley Terminator X Engine Management Systems 550-903

Sale price$719.98 Regular price$799.98
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Ships within 48 hours · Estimated delivery Jul 31 - Aug 5

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Description

Holley Terminator X Engine Management Systems 550-903TERMINATOR X MPFI, LS1 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

TERMINATOR X MPFI, LS1

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:

  • For GM LS1/LS6 engines with 24x crank reluctor - with EV1 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.
  • On-Board 1bar MAP sensor, is perfect for N/A or Nitrous engine combos. If your combination requires a 2+Bar, we recommend GM 12592525, and our adapter part number 558-416.
  • 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
  • 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
  • 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!
  • 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
  • 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: 24x LS Engine Main Harness - EV1 Injector Harness - Terminator X ECU - ECU Main Power Harness - Bosch LSU 4.9 Wideband Oxygen Sensor - Input/Output Harness - and assorted vacuum adapters.

Application

  • 1998 - 2002 Chevrolet Camaro
  • 1997 - 2004 Chevrolet Corvette
  • 1998 - 2002 Pontiac Firebird

Specs

Brand Holley EFI
Crank Reluctor 24x
Emission Code 3
Ignition Type GM LS 24x
Injector Connector Jetronic / Minitimer (Bosch)
Product Type Terminator X LS MPFI
Terminator LS Options Fuel, Spark
Part Number 550-903
    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: 11379111417

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    4.6 ★★★★★
    Based on 14 reviews
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    Verified Purchase
    VPBN
    Birmingham, US
    ★★★★★ 5
    Love all the Barkbox toys
    Color: Christmas Consuela, Size: Large Dog
    This is our third "Consuela"! Our dogs LOVE these toys, and they are the most durable we can find for our heavy chewers. They really like the ball inside as well. Highly, highly recommend these toys. I won't be buying other toys anymore, just barkbox.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on March 27, 2026
    B
    Verified Purchase
    billy
    New York, US
    ★★★★★ 5
    My dog is a toy destroyer
    Color: Consuela the Cactus - Large, Size: Large Dog, Color: Consuela the Cactus - Large, Size: Large Dog
    I’ve had a hard time trying to find toys that my dog, Zara loves because she’s actually very picky. Ive gotten plenty of Kong toys that are well known to be indestructible but she wants nothing to do with them. Then I got her ropes and that seemed to be good for a while until she was getting sick in the middle of the night from eating all of the string. Stuffed toys aren’t good because she’ll rip them within seconds and eat all of the stuffing. I felt like I’ll never score the perfect toy for her. I found the three layered cactus toy and decided to give it a go. It’s clearly designed to be ripped and destroyed to get the ball in the middle which is actually really cute and fun to see all of the layers. The cactus arms have stuffing and of course that’s the first thing she went for and ate. I had to watch her and make sure I took the stuffing away before she ate it. And before I knew it, she ate half of the first layer fabric lol once she got through the first layer, all she’s been doing is walking around the house with the toy in her mouth. But now she’s tired and passed out on the couch from all of the fun. This toy won’t last long with a toy destroyer but it sure does give them something to do and it’s a cute toy. I do recommend!!
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on July 26, 2024
    K
    Verified Purchase
    Klara Gengler
    Natrona Heights, 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.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on September 25, 2025
    C
    Verified Purchase
    Cassie
    Waukegan, 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
    Charlottesville, 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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