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Holley EFI

Holley EFI Benchtop Harness

Benchtop Test Harness for Firmware Updating, Dash Configuration, and ECU Testing.

Part # 558-127
Estimated shipping date: 01/21/2022
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Designed for benchtop testing and setup of HP, Dominator, Terminator X, Terminator X Max, and Sniper ECU's, as well as 7" dashes. Great for ECU diagnostics, firmware updating, or pre-configuring dash layouts without being in the vehicle. Harness has pre-terminated connectors for the following sensor inputs: CAN, Crank, Cam, TPS, Input #1, P1A, Main Power, and Sniper EFI connectors for a Sniper main harness. Also includes a power switch for quick setup in your workspace. Power and Ground flying leads need to be connected to your battery or power supply. (Not included)


  • Terminated connectors for several EFI inputs
  • Included power switch allows for a quick “install” on your test bench
  • Great for ECU diagnostics that do not require a running engine, firmware updates, or 7” dash calibrations

About Holley EFI

Holley is the new standard in EFI! Whether you're engine swapping your classic car or need to manage 4000 horsepower in your twin-turbocharged drag radial race car, Holley EFI has the solutions you need to get your project up and running better than ever!

Brand Holley EFI
Product TypeHarness
Part Number558-127
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