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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Mimi Emily
Bozeman, US
★★★★★ 5
All 3 dogs, 3 different sizes and ages love it! Can’t go wrong!
Size: Medium, Style: Bristle Bone
Great! Super great! When you HAVE TO GET THEM OUT OF YOUR HAIR! This toy is durable even without the beef flavored insert! I have a Border Collie who has too much energy and an Aussie who can’t sit still and a small stray who is constantly figuring out a way to steal these from the other two! Safe, effective and actually cleans their teeth! This might well be my first Amazon review because this toy deserves it!
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Reviewed in the United States on March 19, 2026
S
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Sarah
Whiting, US
★★★★★ 5
Bully approved
If he wants something to gnaw on he will sit with it but he doesn't really play with it. Which is probably the point. It's lasted. The ends are the most chewed. Overall great for a chewer!
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Reviewed in the United States on June 10, 2026
K
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KenH
Los Angeles, US
★★★★★ 5
Surprisingly Durable
Color: Green
Our dog is an aggressive chewer. She has destroyed other toys meant for "aggressive chewers" in less that 6 hours. This toy has lasted 17 days and it's still going. It does have areas were the seam has given way and a very small amount of stuffing has come out. She has "killed" the squeaker. But the toy is still usable. We just played Tug of War this morning. It will not last forever. It is showing it's "age". But the durability is there. I am ordering more.
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Reviewed in the United States on March 18, 2026
M
Verified Purchase
Matt
Natrona Heights, US
★★★★★ 4
Okay for the money
Color: Green
Kind of durable. My dog loved it tho. Lots of tugs. But also lot of stuffing everywhere
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Reviewed in the United States on May 24, 2026
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Verified Purchase
Barbara Herges
San Leandro, US
★★★★★ 3
Durability and lasting period of toy.
Color: Green
I got this toy for our bulldog. He had a hole in it, which will only progress, within minutes. I took it away until I could find out if there is any kind of warranty. The information says this toy is not for aggressive chewers, yet right in the description and the photo of the toy (that way I knew I was looking at the correct toy), it says for the "aggressive chewer". I am disappointed that even though it isn't how they described, it only lasted minutes before there was damage. Not sure if I would buy another product.
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Reviewed in the United States on December 28, 2025

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