Product Summary

Gen III Hemi Coil-on-Plug Ignition Type

    Key Specs

    MFG. Part #550-1421
    Ignition TypeGen III Hemi Coil-on-Plug
    Tuner StyleTouchscreen Handheld
    Throttle StyleDrive-By-Wire

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    Holley 550-1421 Details

    Introducing Terminator X and X Max Kits for Chrysler GEN III HEMI engines from 2003-2013+ such as the 5.7L, 6.1L and 6.4L engines with the factory Drive-by-Wire throttle body. (Non-VVT only)

  • 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 HEMI 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 EFIs 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 wont break the bank!


    • Plug and play Chrysler GEN III Hemi control - 2003-2006 Engines such as the 5.7L, 6.1L and 6.4L engines utilizing the factory DBW (Drive by Wire) throttle body. (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
    • EV6 injector harness included
    • 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. REMINDER: diagnostic LEDs must face up!
    • FREE EFI Tuning software - For compete control of your Terminator X power plant
  • Application

    Fits 2003-2006 GEN III HEMI engines with EV6 injectors, and a Drive-By-Wire throttle body.


    CARB Warning

    For race/ off road use or for use on pre-1966 vehicles.

    Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway, or if installed in vehicles model-year 1965 or older; motorcycles model-year 1977 or older; or off-highway recreational vehicles (such as off-road motorcycles and all-terrain vehicles) model-year 1996 and older. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.

    Holley 550-1421 Specifications

    MFG. Part #550-1421
    Ignition TypeGen III Hemi Coil-on-Plug
    Tuner StyleTouchscreen Handheld
    Throttle StyleDrive-By-Wire
    Speedway Motors Catalog Part #425-5501421
    Injector ConnectorUSCAR (EV6)
    MAP Sensor IncludedYes
    Transmission ControlNo
    Oxygen Sensor StyleBosch
    GTIN Code090127088067
    Sold in QuantityKit