Uploaded March 2026 | Updated September 2026, 2 weeks ago

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Upgrade your Holley ECU with the latest firmware for Terminator X, HP, and Dominator systems! This update adds powerful new features like selectable O2 sensors, integrated dash/handheld firmware, Ford Godzilla base calibrations, and a built-in output testing tool.

Learn how to safely test injectors, ignition coils, fuel pumps, fans, and more using Holley’s new diagnostic feature. We also cover key safety tips to prevent damage during testing.

Download the free Holley EFI firmware update today and take your tuning to the next level.

Visit: Holley.com for updates and EFI system support

Learn More:

holley.com/support/fuel_injection/terminator_x_and_x_max

holley.com/support/fuel_injection/hp_and_dominator_efi

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