Fuel Injection System Wiring Harnesses - Holley EFI System Manufacturer - In Stock Filter Options - Vendor In Stock Filter Options - Free Shipping on Orders Over $109 at Summit Racing

Holley Sniper 2 EFI Input/Output Wiring Harnesses 558-497

Wire Harnesses, Sniper 2 EFI, Input/Output Harness, Throttle Body Injection, Speed Density Metered, 6-pin Female Connector, Each

Part Number: SNE-558-497

5.0 out of 5 stars ( 4 )

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Holley Terminator EFI Wiring Harnesses 558-420

Fuel Injection System Wiring Harnesses, Holley EFI, Auxiliary Input/Output Harness, Terminator EFI, Gains 4 Inputs/1 Output, Each

Part Number: HLY-558-420

5.0 out of 5 stars ( 2 )

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Holley Dominator EFI Auxiliary Harnesses 558-404

Fuel Injection Systems Wiring Harnesses, Dominator EFI, J4 Auxiliary Harness, MPFI, Speed Density/Throttle, 26 Input/Outputs, Connector Included, Kit

Part Number: HLY-558-404

4.0 out of 5 stars ( 1 )

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Holley GM Distributor Wiring Harness Adapters 558-304

Wiring Harnesses, Holley EFI, HEI Distributor, Adapter Harness, Small Cap, Computer Controlled, for Avenger, HP, Dominator EFI Systems, Each

Part Number: HLY-558-304

5.0 out of 5 stars ( 2 )

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Holley Replacement Fuel Injector Wiring Harnesses 558-214

Fuel Injection System Wiring Harnesses, Holley EFI, Replacement, MPFI, Mass Airflow, Injector Harness, LS Multec 2, Chevy, Truck, 4.8-6.0L, Each

Part Number: HLY-558-214

5.0 out of 5 stars ( 3 )

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Holley Dominator EFI Auxiliary Harnesses 558-403

Fuel Injection Systems Wiring Harnesses, Dominator EFI, J3 Auxiliary Harness, MPFI, Speed Density/Throttle, 17 Input/Outputs, Connector Included, Kit

Part Number: HLY-558-403

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Holley Replacement Fuel Injector Wiring Harnesses 558-501

Fuel Injection System Wiring Harnesses, Holley EFI, GM LS 58X Crank Sensor, Includes Power, EV6 Injector, Main Harnesses, for HP, Dominator ECUs, Kit

Part Number: HLY-558-501

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Estimated Ship Date: Mar 9, 2026 if ordered today

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Estimated Ship Date: Mar 9, 2026 if ordered today

Holley EFI Benchtop Harnesses 558-127

Wiring Harnesses, Holley EFI, Benchtop Harness, Test Harness, EFI Input Connectors, Power Switch, for HP, Dominator, Terminator, Sniper ECUs, Each

Part Number: HLY-558-127

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Holley Replacement Fuel Injector Wiring Harnesses 558-211

Fuel Injection System Wiring Harnesses, Holley EFI, Replacement, Gen III Hemi, Injector Harness, Bosch/Jetronic/Holley, for HP, Dominator EFI, Each

Part Number: HLY-558-211

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Holley EFI Systems Wiring Harnesses 558-411

Fuel Injection System Wiring Harnesses, Dominator EFI, GM LSx, Dual Drive-by-Wire Harness, for Throttle Bodies to Dominator EFI Systems, Each

Part Number: HLY-558-411

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Holley Replacement Fuel Injector Wiring Harnesses 558-209

Fuel Injection System Wiring Harnesses, Holley EFI, Replacement, Ford V8, Injector Harness, Multi-Port, for HP, Dominator EFI Systems, Each

Part Number: HLY-558-209

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Holley Replacement Fuel Injector Wiring Harnesses 558-210

Fuel Injection System Wiring Harnesses, Holley EFI, Replacement, Gen III Hemi, Injector Harness, Stock/USCAR Injectors, for HP, Dominator EFI, Each

Part Number: HLY-558-210

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Summit Racing™ EFI CAN Splitters SUM-890521

Fuel Injection System Wiring Harnesses, EFI CAN Splitters, 48 in. Length, for Use with Holley Terminator X or Sniper EFI Systems, Each

Part Number: SUM-890521

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Holley Drive-By-Wire Throttle Body Wiring Harnesses for 2011-2014 F-150, MUSTANG - 558-422

Fuel Injection System Wiring Harnesses, Holley EFI, Ford Coyote, Drive-By-Wire Harness, Multi-port Style, for HP/Dominator EFI System, Ford, 5.0L, Kit

Part Number: HLY-558-422

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Holley EFI Systems Wiring Harnesses 558-115

Wiring Harnesses, Holley EFI, Gen III Hemi, Throttle Position, Idle Air Controls, Factory Connectors, Chrysler, Dodge, Jeep, Hemi, Early Model, Each

Part Number: HLY-558-115

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Estimated Ship Date: Mar 9, 2026 if ordered today

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Estimated Ship Date: Mar 9, 2026 if ordered today

Holley EFI Systems Main Wiring Harnesses for 2011-2017 F-150, MUSTANG - 558-110

Wiring Harnesses, Holley EFI, Coyote, with TI-VCT/Stock Coils, Main Harness, MPFI, for HP, Dominator, EFI Systems, Ford, 5.0L, Each

Part Number: HLY-558-110

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Holley EFI Systems Wiring Harnesses 558-112

Wiring Harnesses, Holley EFI, Main Harness, 58X LS TBI, for Terminator, Terminator Stealth, Throttle Body Systems, Chevy, Each

Part Number: HLY-558-112

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Holley EFI CAN Adapter Harnesses 558-451

Fuel Injection System Wiring Harnesses, Holley EFI, CAN Adapter Harness, Male to Female Adapter, 12 in. Long, for Racepak or CAN Device, Each

Part Number: HLY-558-451

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Holley EFI Terminator Stealth Main Wiring Harnesses 558-121

Fuel Injection System Wiring Harnesses, Holley EFI, Terminator Stealth 2x4, Upgrade Main Harness, Plug-and-Play, Universal, Kit

Part Number: HLY-558-121

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Holley EFI Systems Wiring Harnesses 558-113

Wiring Harnesses, Holley EFI, Ford 2V/4V Modular, Main Harness, Multi-Port Fuel Injection, for Holley Smart Coils, HP EFI System, Ford, 4.6-5.4L, Each

Part Number: HLY-558-113

Not Yet Reviewed

Estimated Ship Date: Mar 9, 2026 if ordered today

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Estimated Ship Date: Mar 9, 2026 if ordered today

Holley EFI Systems Main Wiring Harnesses 558-141

Wiring Harnesses, Holley EFI, Main Harness with Smart Coils, 7.3L Godzilla, Ford Each

Part Number: HLY-558-141

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Estimated Ship Date: Mar 9, 2026 if ordered today

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Estimated Ship Date: Mar 9, 2026 if ordered today

Holley EFI Terminator X Drive-By-Wire Throttle Body Wiring Harnesses 558-469

Fuel Injection System Wiring Harnesses, Holley EFI, 7.3 L Godzilla, Drive-by-Wire, Throttle Body Harness, for Terminator X, Ford, Each

Part Number: HLY-558-469

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Holley EFI Systems Wiring Harnesses 558-439

Fuel Injection System Wiring Harnesses, Holley EFI, Terminator, Throttle Body Systems, Plug-and-Play, Upgrade Harness, for 205 lb./hr. Injectors, Each

Part Number: HLY-558-439

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Estimated Ship Date: Mar 9, 2026 if ordered today

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Estimated Ship Date: Mar 9, 2026 if ordered today

Holley EFI Systems Wiring Harnesses 558-502

Fuel Injection System Wiring Harnesses, Holley EFI, GM LS 58X Crank Sensor, Power, Bosch Injector, Main Harnesses, for HP, Dominator ECUs, Kit

Part Number: HLY-558-502

Not Yet Reviewed

Estimated Ship Date: Mar 9, 2026 if ordered today

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Estimated Ship Date: Mar 9, 2026 if ordered today

Holley EFI Systems Wiring Harnesses 558-504

Fuel Injection System Wiring Harnesses, Holley EFI, Universal, V8 MPFI Harness, with Main, Power, Bosch Injector Harnesses, for HP, Dominator ECU, Kit

Part Number: HLY-558-504

Not Yet Reviewed

Estimated Ship Date: Mar 9, 2026 if ordered today

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Estimated Ship Date: Mar 9, 2026 if ordered today