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 Aug 7 - Aug 12

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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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    4.5 ★★★★★
    Based on 6 reviews
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    Verified Purchase
    JessicaSB
    Pawtucket, US
    ★★★★★ 5
    Aggressive chewer puppy approved
    Color: Cinamutt Roll - Large, Size: Large
    My aggressive chewer puppy loves this. It is pretty sturdy. He hasn't destroyed it yet and he's had it for over 3 months now.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on March 10, 2026
    J
    Verified Purchase
    Jordan
    Belleville, US
    ★★★★★ 1
    Pieces off in minutes.
    Color: Origin - Large, Size: Medium/Large Dog
    My pup chewed pieces off in minutes.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on June 6, 2026
    A
    Verified Purchase
    Amazon Customer
    Lake Worth, US
    ★★★★★ 3
    Pretty hard to clean
    Color: Cinamutt Roll - Large, Size: Large
    We've had this for about a week now. I have 2 dogs, one small one about 55lb. I bought this for my big girl, but lil man is determined to get the best of this toy. Usually they don't both go after the same toys, so this is interesting. The trouble is, neither one of them can get all the treats out if something makes it all the way down into the crevice. It's surprisingly deep. The up side is that they'll try for quite a while before giving up. The down side is even if you put it in the top rack of the dishwasher, something stuck deep in there isn't going anywhere until you dig it out yourself. I tried a plastic knife but it broke the second time I used it in there. I wound up using the metal handle of a reusable straw cleaner. Which then I had to wash that, too. Then it needs to dry overnight before it can be used again. All in all, the dogs like it fine, it's gross to scrape out and wash, takes longer than most toys to dry, and I have the feeling that will eventually cause me to pass it to someone else's dog long before my two have gotten tired of it. At this point I'm pulling out of the toy rotation for a week or two because I'm not ready to clean it a third time.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on November 16, 2024
    D
    Verified Purchase
    Dogmom120
    Dallas, US
    ★★★★★ 5
    Hyena Proof
    Color: Acorn - Large, Size: Large
    I have an American Bulldog that would chew a brick if he didn’t have an alternative lying around. They won’t last forever (nothing does) but we’ve had two of these over the course of a year and for him that is nothing short of a miracle. And that is daily chewing like it’s his job. I highly recommend the Acornucopia for aggressive chewers with jaws like hyenas…so it’s probably great for your dog too.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on June 7, 2026
    B
    Verified Purchase
    Becky L
    Massapequa, US
    ★★★★★ 5
    Great Product!
    Size: 5.75 inch (Pack of 1)
    My dog is a chewer! She can chew through most chew toys in a day. This has been a lifesaver! She chews on it but has not been able to get any pieces off of it. It is Durable and she loves it! This is a great item. I intend to buy more like this. It is a great product!
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on June 3, 2026

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