Ignitions and Electrical› Computers, Chips, Modules and Programmers
Holley
TERMINATOR X MPFI, 4.8-6.0 EARLY TRUCK
SKU: H00E 550-904
Moderate — 2–4 hours
Description
Part #: 550-904
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!
Features:
- For GM LS Engines with 24x crank reluctor and Multec 2 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.
- MAP Sensor vacuum hose adapters (1/8th - ┬╝ and 3/16ths)
- 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
- 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
- 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!adjustable through included 3.5" f
- 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 - Multec 2 Injector Harness - Terminator X ECU - ECU Main Power Harness - Bosch LSU 4.9 Wideband Oxygen Sensor - Input/Output Harness - and assorted vacuum adapters.
24x Crank - 1x Cam - Multec 2 Injectors - 3.5 in. Touchscreen
MIA's Description
Fitment
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Available on iOS & Android
Specifications
| Brand | Holley |
| Part Number | H00E 550-904 |
| Weight | 9.03 lb |
Videos
Terminator X Full Install and Overview
Holley Terminator X Max install for newbies! Easier than you think!
Silverado Holley Terminator X Integration (Part 1)
How to Install a Holley Terminator X (Step by Step)
Converting Stock Computer to Holley Terminator X on The 6.0 LS Nova!
How To: Install Terminator X EFI on any LS Engine
Installing Holley Terminator X On my 6.0 Swapped Cateye Silverado! *Part 1*
Holley terminator X integrated with stock ECU on Silverado 03-07
LS 5.3 Swap, Holley Terminator X Max installation on 1981 El-Camino with 4L60E transmission.
Holley Terminator X Install
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Buy with Confidence
Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
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