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Vehicle Info NeededHOLLEYPART NUMBER: 510-558-127
558-127 Benchtop Test Harness For HP, Dominator, Terminator X/Max, Sniper ECUs
$24995
Ships on 09/09/2026
Lowest Price GuaranteeBench Test Harness
Benchtop Test HarnessHP, Dominator, Terminator X/Max, Sniper ECUs Diagnostic/Calibration Pre/Terminated Connectors Sold Individually
Holley 558-127 Features:
- Included power switch
- Bench testing for select ECUs and 7 in. dash calibration
- Ideal for diagnosing engines when they are off
- Optimal for ECU diagnostic, firmware updating, and pre-configuring dash layouts
- Terminated connectors for multiple EFI inputs
- Pre-terminated connectors for CAN, crank, cam, TPS, input (1), and P1A sensors
- Main power, and Sniper EFI main harness connectors
Emissions Note:
This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.
CLICK THIS LINK FOR IMPORTANT CARB & EPA EMISSIONS INFORMATION ABOUT THIS PART
Complete All Your Holley EFI Wiring Needs
Holley EFI wiring harnesses are compatible with Holley's Avenger, HP, Terminator, and Dominator EFI Systems. EFI harnesses for various Holley systems can consist of the main harness, transmission harness (if applicable), injector harness, ignition/coil harness, throttle body harness, and auxiliary harnesses to access features of your Holley EFI system.
Part TypeWiring Harness
Product LineHolley Avenger, HP, Terminator and Dominator EFI Wiring Harnesses
BrandHOLLEY
Package Height15.0
Package Width16.0
Package Length26.5
Weight1.0 PG
Part CategoryPerformance Parts
QuantitySold individually
Part FitmentSemi Universal
Vendor Part Number558-127
Package Qty1
Package TypeEA
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