Holley Terminator EFI Wiring Harnesses 558-420 Fuel Injection System Harnesses, EFI, Auxiliary Input/Output Harness, EFI, Gains 4 Inputs/1 Output, Each
Holley Terminator EFI Wiring Harnesses 558-420 Fuel Injection System Harnesses, EFI, Auxiliary Input/Output Harness, EFI, Gains 4 Inputs/1 Output, Each
Description
EFI Wiring Harness - Input / Output - Holley Terminator EFI - Each
Data: v2 - Desc: v4.2 - Upd: 2026-11-08 02:14:53
Features
Vehicle Compatibility and Return Conditions.
This item was designed and engineered in the USA for US domestic vehicles. OBD tools, ECUs, dongles, programmers, and tuners may have limited compatibility with vehicles outside the USA due to regional differences in emission standards and system configurations. Some features and functionality may vary depending on the vehicle and location.
Some electronic tuning devices and programmers require activation, registration, or pairing with a specific vehicle’s VIN (Vehicle Identification Number). Once activated or paired, these devices may become permanently associated with that vehicle, restricting or preventing their use on another vehicle, resticting our ability to offer returns or exchanges.
Please review the product details and images to ensure it meets your needs. For clarification or assistance, feel free to contact a StreetFX agent. Note: Returns are not accepted for special order or tuning products unless the unit is deemed faulty.
Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.
Specifications
Reference Information
| Reference Data (Provide these details to our support team) | |
|---|---|
| Brand Name/s | Holley, Hilborn, Holley Efi, Retrobright, Terminator X |
| StreetFX SKU | hly558-420 |
| SFX Item ID | 4782203 |
| Accounting SKU | hly-558-420 |
| Manufacturer SKU | 558-420 |
| Manufacturer UPC | 090127688519 |
| Alternative References | 558-420, HLY-558-420, HOL558-420 |
Fuel Injection System Wiring Harnesses, Holley EFI, Auxiliary Input/Output Harness, Terminator EFI, Gains 4 Inputs/1 Output, Each
Holley Terminator EFI wiring harnesses are replacement throttle body wiring harnesses and engine control wiring harnesses for specific Electronic Fuel Injection kits. These relays allow you to perform functions and features that are programmed with your Holley EFI laptop software. The software also contains instructions on how to program them. Holley wiring accessories give you the expertise needed to get the job done right.
| Product Attributes | |
|---|---|
| Brand | Holley |
| Manufacturer's Part Number | 558-420 |
| Part Type | Fuel Injection System Wiring Harnesses |
| Product Line | Holley Terminator EFI Wiring Harnesses |
| UPC | 090127688519 |
| Quantity | Sold individually. |
| Notes | Harness contains four extra input wires and one extra output wire that the base Terminator EFI harness does not contain. |
Compatibility
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