SKU: 5946477168

Holley Terminator X Engine Management Systems 550-909

Sale price$719.98 Regular price$799.98
Save 10%

Pay in installments of $200.00 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 17 - Jul 22

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

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: 5946477168

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.5 ★★★★★
Based on 20 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
M
Verified Purchase
M.J.
Lake Worth, US
★★★★★ 5
Excellent shelf brackets.
Size: 12 Inch, Color: Black
Perfect exactly as advertised. Correct measurement at 12 inches. Product supplies All the screw for mounting. High quality and very sturdy. Used in my pantry. No instructions but don’t really need.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 7, 2026
M
Verified Purchase
michael borton
Charlottesville, US
★★★★★ 5
Quality and great looking for everything.
Size: 10 Inch, Color: Black
Easy to use , and works and looks great in the garage.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 14, 2026
G
Verified Purchase
Guadalupe Galan
Charlottesville, US
★★★★★ 4
Heavy duty brackets!
Size: 8 Inch, Color: Gold, Size: 8 Inch, Color: Gold
These brackets are heavy duty and came with the correct hardware. They were easy to install, the two holes were so helpful to know where to mark them. I think because they’re heavy duty you can place a good amount of weight on your shelves. The only thing I wasn’t happy with is that 4/69 of shelves, the paint was chipping but it was the perfect gold color.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 14, 2026
P
Verified Purchase
Port
Whiting, US
★★★★★ 5
Really nice looking work great
Size: 4 Inch, Color: Black
Great looking
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026
S
Verified Purchase
Sharon
Waukegan, US
★★★★★ 5
Don't hesitate - Great product!
Size: 12 Inch, Color: Black
Superior quality at an unbelievable savings over local retailers. Hardware for hanging included the cheaper plastic lags yet they also included the heavy duty lags, so no tapping in to our supply. Thank you for a great product
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 13, 2025

recommand products