SKU: 75558121275

Holley Terminator X Engine Management Systems 550-909

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 550-909TERMINATOR X MPFI, LS1 W EV6 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.

TERMINATOR X MPFI, LS1 W/ EV6 

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 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.
  • 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 - EV6 Injector Harness - Terminator X 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 24x
Emission Code 3
Ignition Type GM LS 24x
Injector Connector USCAR (EV6)
Product Type Terminator X LS MPFI
Terminator LS Options Fuel, Spark
Part Number 550-909
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: 75558121275

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Sarabreit
Dallas, US
★★★★★ 4
Worth it albeit online claim process need work
I submitted the claim online twice and each time the claim was denied due to missing documents, which I included. Calling the customer service center was helpful. Shout out to UPS, who picked up the returned item and provided a receipt. Still recommend getting protection, might be an exercise of patience but still worth it.
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Reviewed in the United States on April 5, 2026
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lighthead
Alexandria, US
★★★★★ 5
Absolutely buy this insurance for any product you care about!
I usually don't buy the protection plan for appliances, but the combination of previous experiences with milk frothers that inexplicably and quickly failed taught me to do so this time with my Maestri House milk frother, bought for $70. I'm so glad I did! It shorted out at 22 months, and the company refused to help. I filed my claim with Asurion, got a return label immediately, sent it back that day, and was notified within a couple of days that the total cost of the frother was now ready and waiting for me in my Amazon account. It was so easy, so seamless, and so quick! I researched new (non-Maestri House) frothers, and bought a highly-praised one for the same price--with another 3-year plan from Asurion. So well worth a few more dollars to protect an appliance that I can't start my day without!
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Reviewed in the United States on February 14, 2026
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ALEXANDER
Battle Creek, US
★★★★★ 1
First time claim with Asurion, definitely SHADY
This whole thing is really shady. I just called to file a claim for a juicer that I purchased at the same time for coverage. The guy asked for my name, address, than wanted my claim number.... but I was calling to file a claim. I told him I had an order number, so he said Yea give me that. "Now I need your 16 digit credit card number. Thats when I STOPPED. I asked him how does this process work. He said I needed to give him my credit card number first. I repeated ... "can you just tell me how this is going to process so I understand". He then said, "thank you have a blessed day" and hung up. Not odd disconnected, he just hung up. I don't think I'll be buying the Asurion protection anymore. I'll try amazon direct and give an update if I have one. March 12, 2026
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Reviewed in the United States on March 12, 2026
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beckyod
Alexandria, US
★★★★★ 5
So Worth It!!
My Keurig died and I went to order another one. I did "buy it again" because I really loved the last one. It showed my purchase date and I was suprized that I hadn't been it that long. I had purchased the protection plan and decided to go ahead and see if they would cover it, thinking that it would be too complicated to complete, but......It literally took less that ONE MINUTE!!! I printed the return label, took it to the UPS store and within hours had a gift card to my Amazon account! I always add Asurion, but this was the first time I had to use it!!! TOTALLY WORTH the $8 for 3 years protection!! Thank You so much Asurion!!
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Reviewed in the United States on February 6, 2026
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Tman
Waukegan, US
★★★★★ 5
Warranty honored.
Great warranty called they replaced product under the warranty I purchased
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Reviewed in the United States on May 31, 2026

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