SKU: 99700823923

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 4 - Aug 9

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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: 99700823923

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    J
    Jamie K.
    Lake Worth, US
    ★★★★★ 5
    Perfect for Adding Privacy to a Piano Studio
    Size: 2 Panel 8FT W, Size: 2 Panel 8FT W
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    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on May 18, 2026
    J
    Just Me
    Whiting, US
    ★★★★★ 5
    Room Divider That Gives Instant “This Is a Separate Space Now” Energy
    Size: 3 Panel 12FT W
    The Siebwin 3 Panel Folding Privacy Screen is surprisingly effective at changing the feel of a room without requiring construction, commitment, or somebody yelling about load bearing walls. The 12 foot width gives a substantial amount of coverage, making it useful for creating privacy, dividing open areas, blocking visual clutter, or setting up temporary sections within larger rooms. This saved us a ton of time and money in our new studio and enabled us to create a kitchen and office in one room. The wider feet make a huge difference because flimsy room dividers that collapse every time someone exhales too aggressively are deeply annoying. This one feels more stable and grounded once positioned. The folding design makes it easy to move around or adjust depending on the space, and it folds down relatively compactly when not in use. It is basically the introvert curtain wall of dreams. The material has a clean, neutral look that blends well into different room styles without screaming “temporary office cubicle panic.” It works well for apartments, studios, shared spaces, dressing areas, or simply hiding the mountain of chaos you swear you are going to organize tomorrow. Practical, portable, and refreshingly easy to use without turning setup into a three hour emotional event.
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    Reviewed in the United States on May 16, 2026
    S
    Skeetre
    New York, US
    ★★★★★ 4
    It's 2 panels holding 1 big privacy screen. Can't use as 2 separate 4' panels, but works great.
    Size: 2 Panel 8FT W
    This 2 panel privacy screen works well. Assembly was very straight forward, with easily labeled tubes. My son and I had it together in about 10 minutes, which was probably 3 minutes of me telling him to quit playing around and hand me the parts. It feels very sturdy, not likely to fall over or anything. The material fits well, with the Velcro being very strong. Measurements are all very accurate, with all pieces attaching properly. We have a similar privacy screen at work that we have to try and stretch out because the top and bottom Velcro doesn't fit quite right... this model does not have any issues though. The material is thin and light weight, but solid black so that you can't see anything through or behind it. I definitely think it's a great deal for the money. What I think would have given it 5 stars though, is if you had 2 totally separate 4' panels instead of 2 panels with one big screen. It really wouldn't cost any extra to make it so that the screen was in 2 pieces and you could use it as 2 separate panels instead of having to use it as one big panel. It says 2 panel folding privacy screens, but it's really one big one that folds in the middle.
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    Reviewed in the United States on May 25, 2026
    A
    Verified Purchase
    Andy Sims
    Battle Creek, US
    ★★★★★ 5
    better then expected
    Color: Black
    very easy to put together works perfectly! very stable for the side would buy again!
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    Reviewed in the United States on May 21, 2026
    Y
    Verified Purchase
    Yuliet carreño cutiño
    Omaha, US
    ★★★★★ 3
    Divisor de habitaciones
    Color: Black
    La entrega fue perfecta , si debo de decir que en la descripción del producto decía que media 72 ancho x 72 alto pero no fue así su ancho es de 60 .
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    Reviewed in the United States on September 6, 2025

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