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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:
- 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
4.1 ★★★★★
Based on 21 reviews
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Product Reviews
★★★★★ 5
The best dog toy llama!
Color: Llama
My fur baby LOVES his stuffed llama!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 13, 2026
★★★★★ 5
Perfect Squeaky Toy for My Exes Deranged Dog
Color: Multicolor, Color: Multicolor
My ex-beau and I are still friendly and we exchange Christmas presents. This year, I wanted to make sure that his utterly nutty and completely bonkers Aussie, Diego, got a new toy so that he has added enrichment in his enclosure. Diego really enjoyed this toy! A perfect size for him and a loud squeaker, which my ex will undoubtedly appreciate being squeaked non-stop while he is trying to game with his various assortment of video game people. Worth every penny. Diego’s smiling face is proof of his delight in his adorable Slothicorn. Squeak away, Diego! Squeak away!
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Reviewed in the United States on January 14, 2026
★★★★★ 4
Fun
Color: Multicolor
A little smaller than we'd hoped but all in all he's pretty cool and our dogs loved him.
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Reviewed in the United States on October 5, 2025
★★★★★ 5
Worth it!
Color: Llama
Wanted to keep this for myself! Made well, size is perfect for a 90 pound pup, durable enough for a non chewer (she cleans their fur but doesn’t chew anymore). Durable enough that has been left outside during Summer storms and washed/dryed a couple times already (I use a laundry bag) and still has its adorable shape.
Great value for the money, though I might need to buy another one for myself! *^_^*
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Reviewed in the United States on August 1, 2025
★★★★★ 5
Our Doodle's Fav Toy
Color: Multicolor
The first slothicorn toy that we received had a broken squeaker. We were able to quickly and easily get a replacement and send the broken one back. This is one of my pup's favorite toys, although I don't think the horn will last long-- it's the part she likes to chew on the most! At 5lbs, the toy is the same size as my Goldendoodle puppy. I think the toy is overpriced when not on sale (I got on Black Friday promo), so I would encourage waiting for a price drop before purchasing or locating another option that's affordable.
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Reviewed in the United States on January 2, 2026