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- USA
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- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 9 - Jul 14
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:
- 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
4.6 ★★★★★
Based on 2195 reviews
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Product Reviews
★★★★★ 5
Great
Color: 2926 Gold Stainless Steel/Gold Dial
Exactly as shown, perfect
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 26, 2026
★★★★★ 4
Good budget watch
Color: 2926 Silver Stainless Steel/Black Dial
Good watch for a budget, color is good. The pins holding the link together tend to wear out and fall out. Other than that it worked good.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 14, 2026
★★★★★ 5
Nice Watch
Color: 5885 Siver Stainless Steel/hon Dial, Color: 5885 Siver Stainless Steel/hon Dial
Nice watch for the money. I've only had it a week but seems to be keeping good time. From 20 feet away might be mistaken for "Trump Time". The watch design is actually a copy of the Rolex Submariner for a whole lot less money. Several watch companies have copied the Submariner.
I removed one link at a time when resizing the band. By the time I got to the final link, the supplied tool wasn't working. I had to remove the final link with a hacksaw and pliers.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 22, 2025
★★★★★ 1
DIDN'T LAST LONG
Color: 5885 Gold Stainless Steel/Gold Dial
Bought this in June 2025, and only wore it a few times. Recently noticed the time was "off" and the seconds-hand wasn't moving. I thought it sat too long and needed to be wound up. So, I wound...and wound...and wound. Never met any resistance in the crown during clock-wise winding...just continued to spin freely, and the seconds-hand never moved. It's a pretty-looking time piece, but don't waste your money if you expect it to keep time. 👎
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Reviewed in the United States on March 25, 2026
★★★★★ 3
Great watch, terrible resizing tool.
Color: 2926 Silver Stainless Steel/Black Dial
Watch is great, feel heavy, looks beautiful in person. It shines pretty heavily. My main issue is with the resizing tool it comes with. It broke when I tried to use it. Be prepared to buy your own like I did. I can’t say how the fit is yet because I can’t wear it yet. It is not easy to set up.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 19, 2026
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