HOLLEY EFI 558-221 Injection Harness Gm Engines 099998217354

( Brand: Holley Efi ), ( Part Type: Harness Engine ), ( Country Of Origin: Usa ), ( UPC: 099998217354 ), ( Manufacturer Part Number: 558-221 )

Review HOLLEY EFI Direct injection Sub harness Late Gm Gen Engines fits LT

The Holley EFI 558-221 Direct-Injection Sub-Harness is a crucial component for integrating Holley's Electronic Fuel Injection systems into select General Motors Gen I, II, and III engine applications. This sub-harness is meticulously designed to provide a secure and reliable connection between the fuel system components and the Holley EFI system.

The harness itself is engineered with high-quality, OEM-grade wiring. The wires are color-coded and labeled for easy identification and installation. Each connector is designed to fit securely and snugly into its corresponding location, ensuring a proper electrical connection. The sub-harness includes connectors for the fuel pressure regulator, fuel pump, fuel level sensor, and various other fuel system components.

This direct-injection sub-harness is specifically designed to work with Holley's line of EFI systems, including the Holley Sniper EFI and HP EFI series. It's an essential addition to the installation process, as it simplifies the wiring requirements and eliminates the need for custom wiring solutions.

By using this sub-harness, installers can save time and effort during the installation process, as the harness takes care of most of the wiring requirements. It's also a more reliable solution, as the OEM-grade wiring is designed to withstand the rigors of continuous use in a high-performance automotive environment.

In summary, the Holley EFI 558-221 Direct-Injection Sub-Harness is an essential accessory for anyone looking to install a Holley EFI system in a GM Gen I, II, or III engine application. It simplifies the installation process, saves time and effort, and provides a reliable and secure connection between the fuel system components and the Holley EFI system.

The Holley EFI 558-221 direct-injection sub-harness is designed to simplify the installation of Holley's EFI systems in select GM Gen I-V engines. This sub-harness takes care of the wiring for the fuel injectors, crank sensor, cam sensor, and IAC valve. Here are the pros and cons of buying this sub-harness:

1. Simplifies wiring: The Holley EFI 558-221 sub-harness streamlines the installation process by taking care of the wiring for crucial components, making the installation more manageable.

2. High-quality materials: Holley is known for producing high-quality products, and this sub-harness is no exception. It's designed to withstand the rigors of performance applications.

3. Compatibility: This sub-harness is compatible with a wide range of GM Gen I-V engines, including popular models like the LS1, LS6, and LS7.

4. Time-saving: By eliminating the need to source and install individual wires, this sub-harness saves time during the installation process.

5. Improved reliability: The use of high-quality materials and proper wiring techniques ensures that the sub-harness is more reliable than attempting to create your own wiring harness.

1. Cost: The Holley EFI 558-221 sub-harness is a premium product, and its price point may be higher than some DIY enthusiasts are willing to pay.

2. Limited flexibility: Since this sub-harness is designed for specific applications, it may not offer the same level of customization as creating your own wiring harness.

3. Availability: Depending on the specific GM engine and Holley EFI system you're using, this sub-harness may not be readily available, requiring a potential delay in your project.

In conclusion, the Holley EFI 558-221 direct-injection sub-harness offers several advantages, including simplified installation, high-quality materials, compatibility with various GM engines, time-saving, and improved reliability. However, it comes with some drawbacks, such as a higher cost, limited flexibility, and potential availability issues.

If you're looking for a straightforward and time-saving solution to installing the wiring for critical components in your GM Gen I-V engine using a Holley EFI system, this sub-harness is an excellent investment. On the other hand, if you're on a tight budget, prefer a more custom solution, or have the time and patience to source and install individual wires, other options may be more suitable for you. Ultimately, the decision depends on your specific needs, preferences, and resources.

part # 558221 prices

• $149.95-$233.95

specifications injectiopug:

• for models: Lt
• brand: Holley Efi
• part type: Harness Engine
• country of origin: Usa
• upc: 099998217354
• manufacturer part number: 558-221

offer injectiopug:

• sold: 0
• started: March 31, 2026
• availability: In Stock
• quantity: 2
• options: Ship-to-home

general injectiopug:

• condition: New
• Air Fuel Delivery > Fuel Injection Parts > Additional Fuel Injection Parts

shipping injectiopug:

• type: Fixed
• service: Standard
• cost: $15.99
• transit: 3-7 Days
• class: Standard

payments injectiopug:

• credit card: Diners-club
• wallet: Paypal
• other

seller injectiopug:

• rating: 99.3%
• # reviews: 623350

returns injectiopug:

• time: 30 Days
• paid by: Seller
• policy: Returns Accepted

Holley Efi 558-221 Is Similar To:

• Holley Efi 534-244 Ls Billet Fuel Rails Truck Intakes Open Box Missing Hardware (32.3% similar) $233.95–$236.27. (September 20th, 2024)
• Holley Efi 12-851 Vr Series Fuel Pressure Regulator 2-port Adjustable High (36% similar) $449.95–$460.95. (September 30th, 2024)
• Holley 534-245 Aluminum Billet Fuel Rail Kit Truck Intake For Gm Ls1/ls2/ls6 (32.9% similar) $205.00–$349.95. (January 3rd, 2025)
• Holley Efi 534-103 Fuel Injector And Insulator Retainer Kit - (46.7% similar) $35.95. (January 6th, 2025)
• Holley 557-200 Efi 3 Port Boost Control Solenoid Valve (26.2% similar) $186.95–$221.75. (January 13th, 2025)
• Trans-dapt Performance 086923022008 Trans-dapt For Sb Chevy Tbi On To Holley 4bbl Manifold- Rear Mount Carburetor (18% similar) $49.99–$116.07. (February 10th, 2025)
• Holley 558-452 - Can Adapter Harness 4ft Male To Female (39.7% similar) $28.50–$59.55. (February 22nd, 2025)
• Holley Efi 558-418 Gen Iii Hemi Drive-by-wire Harness - Late Pedal (50.7% similar) $255.95–$271.82. (March 11th, 2025)
• Holley Efi 300-685bk 105mm Throttle Body Adapter Billet Black Finish (33.3% similar) $104.95. (March 16th, 2025)
• Holley Efi 534-209 Ls Hi-flow Fuel Rails Ls1 Ls2 Ls3 Ls6 And L99 Factory Intakes (34.6% similar) $239.99–$258.07. (March 17th, 2025)
• Holley Efi 300-676bk 105mm Throttle Body Adapter Cast Black Finish (33.8% similar) $52.95. (March 29th, 2025)