SKU: 91521065717

Holley Terminator X MAX Engine Management Systems 550-931

Sale price$899.98 Regular price$999.98
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Description

Holley Terminator X MAX Engine Management Systems 550-931TERMINATOR X MAX MPFI W DBW Take control of your LS engine with Terminator X Max! 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 Max features real time fuel learn, high impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs and

TERMINATOR X MAX MPFI W/DBW

Take control of your LS engine with Terminator X Max! 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 Max 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. Part number 550-931 also has Drive-By Wire Throttle Body control. Terminator X Max 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 MAX has the features and technology you need at a price that won't break the bank!

Features:

  • Designed for GM 4.8/5.3/6.0 LS Truck Engines and LS2/LS3 with 58x Crank, 4x Cam and a Drive-By-Wire Throttle Body, with 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.
  • 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.
  • 4 Outputs – Ground, PWM - , for accessories such as; fans, boost control, nitrous control, IAC Kit, and More
  • 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
  • Recommended Pedal part number - 10379038
  • Includes: 58x/4x LS Engine Main Harness - EV6 Injector Harness - DBW Throttle Body Harness - Terminator X MAX 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 Max LS MPFI
Terminator LS Options Fuel, Spark, Drive-by-Wire
Part Number 550-931
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: 91521065717

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JENNY COLLINS
Birmingham, US
★★★★★ 4
Decent Tux but no customer service
Size: XX-Large, Color: Deep Grey
Decent tux for the money. Wish that we could have ordered different sizes for the jacket and the pants. The vest/jacket fits great but the pants were too big. Ended up having to buy separate pants. The add says that if you email them for a different size, they will help you out, but we never heard anything back from our email.
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Reviewed in the United States on November 15, 2025
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Jokenyatta Hampton
Bozeman, US
★★★★★ 5
Size is right
Size: X-Small, Color: Deep Grey
At first I was afraid the tux wouldn't arrive on time for me to see how it fit my son. Now that is has, I realized I was worried for nothing...it fits perfectly!!!! Just follow the size chart. Thank you so much for this inexpensive option!!!!!
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Reviewed in the United States on May 20, 2026
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jessica
Draper, US
★★★★★ 5
Worth it! Good quality for the price
Size: Large, Color: Black Collar White, Size: Large, Color: Black Collar White
Good quality! My husband loved this tux for our elopement, and it looked great on him. We just steamed out the wrinkles, and it looked flawless.
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Reviewed in the United States on March 7, 2026
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jessica thacker
Lowell, US
★★★★★ 5
Great suit
Size: Medium, Color: Black, Size: Medium, Color: Black
Suit fit well no wrinkles upon arrival the quality was great
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Reviewed in the United States on April 10, 2026
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M
Los Angeles, US
★★★★★ 4
💜
my 6’4” husband wore this to our wedding. it looked amazing on him 💜 everything fit pretty good except for the jacket part; that was a little big. it may fit someone who weighs a little more but my husband weighs about 165lbs. we had to tailor it a little bit. other than that, very beautiful suit.
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Reviewed in the United States on December 19, 2025

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