Holley EFI Kit Terminator X Max 58X Crank 4X Cam/ EV1 Injector/ DBW Throttle Body Control For GM LS2/ LS3 Engines



  • Real-Time Fuel Map Learning
  • Precise Tuning Control
  • Plug-And-Play Installation
  • Made In The USA
MSRP $2,094.00
You save 10%

Holley Terminator X Max EFI Kit for GM LS2 and LS3 Engines with 58X Crank 4X Cam, EV1 Style Fuel Injectors, and Drive-By-Wire Throttle Body Control.

The Holley Terminator X Max EFI Kit (550-933) provides your GM LS2/LS3 engine with a modern integrated fuel and ignition controller capable of tremendous power and customization. The system is incredibly versatile, featuring high-impedance injector drivers that can safely power most LS/EFI injectors and real-time fuel map learning that allows for accurate tuning control. Additionally, the kit comes with up to four outputs and inputs, including input triggers for boost control solenoids with time, gear, RPM, and speed-based safeties.

Features and Benefits:
- Real-time fuel map learns and tunes base fuel table
- High impedance injector drivers safely power most LS/EFI injectors
- Utilizes Bosch LSU 4.9 wideband to relay AFR information
- Accurate readings and precise tuning control
- Four outputs for Ground, PWM, fans, boost/nitrous control, IAC kit, and more
- Four inputs for 12V, 5V, ground, frequency, pressure sensors, and activation triggers
- Boost control solenoids for time, gear, RPM, speed, and safeties
- Progressive nitrous control allows single-channel wet or dry
- Non-progressive nitrous control for rich/lean safeties and target closed loop AFR
- Onboard diagnostics LEDs monitor ECU power, engine run, and wideband status
- Easily identify critical engine issues and monitor crank/cam signal
- Plug-And-Play compatible with Holley analog-style gauges, shift lights, and modules
- Compatible with the soon-to-come Holley 12.3” digital dash support
- Free EFI Tuning Software for complete control of your Terminator X power plant
- Made in the USA

The nitrous controls are available in progressive configurations with wet or dry single channels or non-progressive configurations with rich/lean safeties and target closed loop AFR reading capabilities all via a Bosch LSU 4.9 wideband sensor. The onboard diagnostic LEDs allow you to monitor your TPS calibration and other engine issues quickly at a glance. The industry-leading software suite allows full laptop access for even greater control over your system. With a plug-and-play installation, the Holley Terminator X Max EFI Kit is designed to give any level of motor enthusiast access to a reliable and efficient ignition control system suitable even for professional applications.

Kit Includes:
- 58X/4X LS engine main harness
- EV1 injector harness
- Drive-By-Wire throttle body harness 
- Terminator X Max ECU
- ECU main power harness 
- Bosch LSU 4.9 wideband oxygen sensor 
- Input/output harness 
- Assorted vacuum adapters

Tech Tip 1:
- Onboard 1bar MAP sensor is perfect for N/A or nitrous engine combos. If your combination requires a 2+Bar, we recommend GM P/N: 12592525 and Holley adapter P/N: 558-416.

Tech Tip 2:
- 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.

Tech Tip 3:
- 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.

Tech Tip 4:
- The compact ECU size allows you to mount it virtually anywhere. Remember, diagnostic LEDS must face up!

Tech Tip 5:
- Recommended pedal P/N: 10379038

Vehicle Fitment:
- Designed for GM 4.8/5.3/6.0 LS Truck and LS2/LS3 Engines with EV1 Injectors
- For engines with 58X Crank 4X Cam, Drive-By-Wire Throttle Body

California Residents: Proposition 65 Warning

Related Categories: Mustang Parts, Mustang Electrical & Wiring, Mustang EFI Engine & Injector Harnesses, Mustang Engine, Ford Bronco Parts

Only for use on pre-pollution controlled vehicles: This product can be used on vehicles that were manufactured before emissions control regulations were imposed. Pre-pollution vehicles are defined as:

  • 1965 and older U.S. manufactured California certified vehicles
  • 1967 and older U.S. manufactured federally certified vehicles

Installation Difficulty


Intermediate skill is required for this installation.

Vehicle Fitment

This product will fit the following Bronco years:

This product will fit the following C/K years:

  • 1988,
  • 1989,
  • 1990,
  • 1991,
  • 1992,
  • 1993,
  • 1994,
  • 1995,
  • 1996,
  • 1997,
  • 1998,

This product will fit the following C10 years:

This product will fit the following F-100 years:

  • 1948,
  • 1949,
  • 1950,
  • 1951,
  • 1952,
  • 1953,
  • 1954,
  • 1955,
  • 1956,
  • 1957,
  • 1958,
  • 1959,
  • 1960,
  • 1961,
  • 1962,
  • 1963,
  • 1964,
  • 1965,
  • 1966,
  • 1967,
  • 1968,
  • 1969,
  • 1970,
  • 1971,
  • 1972,
  • 1973,
  • 1974,
  • 1975,
  • 1976,
  • 1977,
  • 1978,
  • 1979,

This product will fit the following Mustang years:

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