Products to Compare (max of 3)
Compare These Parts
Talk to the Experts. Call 800.979.0122, 7am-10pm, everyday.
Since 1952
Talk to the Experts. Call 800.979.0122
Shop By
Street Race Truck More... The Toolbox
Add to Cart
Holley 550-1225 Terminator X, 2007-13 Gen III Hemi, EV6 Injectors
Holley 550-1225 Terminator X, 2007-13 Gen III Hemi, EV6 Injectors

Holley 550-1225 Terminator X, 2007-13 Gen III Hemi, EV6 Injectors

Universal Fit, Gen III Hemi Coil-on-Plug Ignition Type, USCAR (EV6) Injector Connector

0 Reviews | 0 Answered Questions
Factory Shipped
Ships FREE
Store Pickup Availability
Lincoln, NE -
Phoenix, AZ -
Select your vehicle to verify fitment.
Select Vehicle
Holley 550-1225 Terminator X, 2007-13 Gen III Hemi, EV6 Injectors
Holley 550-1225 Terminator X, 2007-13 Gen III Hemi, EV6 Injectors
Holley 550-1225 Terminator X, 2007-13 Gen III Hemi, EV6 Injectors
Holley 550-1225 Terminator X, 2007-13 Gen III Hemi, EV6 Injectors
Zoomed In Image
We estimate this item will ship on or before March 4th.
Part # 4255501225
Save 10%
Call to Order
Add to Buildlist
Videos & Articles


Ignition Type:
Gen III Hemi Coil-on-Plug
Injector Connector:
MAP Sensor Included:
Tuner Style:
Touchscreen Handheld
Transmission Control:
Throttle Style:
Cable Driven
Oxygen Sensor Style:
MFG. Part #:
GTIN Code:
Sold in Quantity:


Introducing Terminator X for Chrysler GEN III HEMI engines from 2003-2013+ such as the 5.7L, 6.1L and 6.4L engines. (Non-VVT only)Terminator X features real-time fuel learn, high impedance injector drivers, integrated 1bar MAP sensor, and 4 programmable inputs and outputs. These are ideal for electric fans, boost control solenoids, progressive nitrous control, and much more.Terminator X ECU comes fully loaded with base maps for common Gen III HEMI engine combinations to get you out of the garage and on the road/track fast. The included 3.5" LCD touch screen handheld contains an easy to use calibration wizard as well as tuning and gauge display functions.Included with Terminator X is Holley EFI's industry leading support, easy to use software suite that allows full laptop access/compatibility for advance users. Whether you're building a budget beater or full on race car, Terminator X has the industry leading features and technology you need at a price that won't break the bank.


  • Plug and play engine control (for Chrysler GEN III HEMI control from 2003-2013+ Engines such as the 5.7L, 6.1L and 6.4L engines. (Non-VVT only)
  • Plug and Play compatible with Holley EFI accessories - Analog gauges, shift lights, modules, and both 6.86" and 12.3" Pro Dash
  • EV1 or EV6 injector harness included (depending on your injector configuration)
  • High Impedance Injector drivers power Holley EFI and most stock injectors -Injector support chart found in instructions (will not support low impedance injectors)
  • Included Bosch LSU 4.9 wideband O2 sensors for accurate readings and precise tuning control
  • Built in 1bar MAP (manifold absolute pressure) sensor included - For Boosted applications - internal MAP sensor can be disabled and utilize external MAP sensor harness (kit includes a terminated connector for seamless installation)
  • Vacuum hose adapters included - (1/8", 1/4", and 3/16" sizes)
  • 4 inputs - 12v, Ground, 5v, and frequency for items like pressure sensors, activation triggers, nitrous activation, or trans brake
  • Boost Control - boost vs. time, boost vs. gear, boost vs. RPM, boost vs. speed, and boost safeties
  • Nitrous Control - channels for wet or dry, progressive or non-progressive, rich/lean safeties, and target closed loop AFR (Air/Fuel Ratio)
  • Advanced Tables - ( 4x 1D tables, 1x 1D gear table, 4x 2D table, and 1x 2D gear tables) for nearly unlimited table configuration options
  • On-board diagnostic LEDS - ECU power, engine run, TPS calibration, cam signal, and more! Identify critical engine parameters at a glance
  • 3.5" touchscreen handheld included - Internal data-logging, custom gauge display, and calibration wizard allow quick building bases tunes for any Domestic V8 engine
  • Compact ECU (Engine Control Unit) - At only 7.45" x 4.1" x 1.66" the compact packaging allows mounting virtually anywhere (XMAX ECU = 9.6" x 4.1" x 1.66"). REMINDER: diagnostic LED's must face up!
  • FREE EFI Tuning software - For compete control of your Terminator X power plant

Quick Start

Harness Instructions


Fits 2007-2013+ GEN III HEMI engines with EV6 injectors

Terminator X ECU's are designed to be mounted with the LED's facing up.

Important Messages

  • This item ships directly from the manufacturer. It may take an additional 25 business days for Holley to ship this item.
  • Get FREE shipping when your order includes this item and exceeds $99! Ground shipping only in the contiguous US.
  • This item ships via Ground Shipping only. Expedited and Air shipping options are not available.
Some parts are not legal for use in California or other states with similar laws/regulations

Related Products

More Like This


Q & A

Videos & Articles

You May Also Like