Fuel Injection System Wiring Harnesses

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 )

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

FAST XFI Fuel Injector Harnesses 301201

Wiring Harness, Fuel Injector, FAST XFI, Chevy, 18736542 Firing Order, Each

Part Number: FST-301201

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Jun 29, 2026 if ordered today

...Loading

Estimated Ship Date: Jun 29, 2026 if ordered today

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

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

Haltech Nexus Rebel LS Injector Sub-Harnesses HT-186501

Wiring Harness, Fuel Injector Sub-Harness, EV1, Nexus Rebel LS, Chevrolet, LS, Each

Part Number: HTH-HT-186501

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

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

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

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

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

Holley Drive-By-Wire Throttle Body Wiring Harnesses 558-437

Fuel Injection System Wiring Harnesses, Holley EFI, Hemi Drive-By-Wire, Throttle Body Harness, for Holley Dominator EFI Only, Dodge, 5.7-6.4L, Each

Part Number: HLY-558-437

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

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

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

Holley EFI Systems Wiring Harnesses 558-203

Fuel Injection System Wiring Harnesses, Holley EFI, 6 Cylinder, MPFI, SFI, TBI, Injector Harness, for HP, Dominator EFI Systems, Universal, Each

Part Number: HLY-558-203

Not Yet Reviewed

Estimated Ship Date: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 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

Not Yet Reviewed

Estimated Ship Date: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 2026 if ordered today

FAST XFI Fuel Injector Harnesses 301200

Wiring Harness, Fuel Injector, FAST XFI, Chevy, 18436572 Firing Order, Each

Part Number: FST-301200

Not Yet Reviewed

Estimated Ship Date: Jun 29, 2026 if ordered today

...Loading

Estimated Ship Date: Jun 29, 2026 if ordered today

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: May 14, 2026 if ordered today

...Loading

Estimated Ship Date: May 14, 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: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 2026 if ordered today

Holley Replacement Fuel Injector Wiring Harnesses 558-207

Fuel Injection System Wiring Harnesses, Holley EFI, Replacement, Injector Harness, Unterminated Base, Bosch EV1 Style, with Connector, 16-piece, Set

Part Number: HLY-558-207

Not Yet Reviewed

Estimated Ship Date: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 2026 if ordered today

Holley EFI Systems Wiring Harnesses 558-111

Wiring Harnesses, Holley EFI, Main Harness, 24X LS TBI, for Terminator, Terminator Stealth, Throttle Body Systems, Chevy, Each

Part Number: HLY-558-111

Not Yet Reviewed

Estimated Ship Date: May 12, 2026 if ordered today

...Loading

Estimated Ship Date: May 12, 2026 if ordered today

Holley EFI Systems Wiring Harnesses 558-101

Wiring Harnesses, Holley EFI, Replacement Harness, Multi-Port, Speed Density Metered, for Avenger, HP, Dominator, EFI Systems, with Stealth Ram, Each

Part Number: HLY-558-101

Not Yet Reviewed

Estimated Ship Date: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 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: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 2026 if ordered today

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

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

Holley EFI Systems Wiring Harnesses 558-510

Fuel Injection System Wiring Harnesses, Holley EFI, Coyote Ti-VCT, with Main, Power, Injector, Coil Harnesses, for HP, Dominator ECU, Ford, 5.0L, Kit

Part Number: HLY-558-510

Not Yet Reviewed

Estimated Ship Date: May 14, 2026 if ordered today

...Loading

Estimated Ship Date: May 14, 2026 if ordered today

FAST EZ-EFI 2.0 Replacement Main Wiring Harnesses 30308

Main Wiring Harness, EZ-EFI 2.0 Replacement, Throttle Body Injection Style, Universal, FAST, Each

Part Number: FST-30308

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Jun 29, 2026 if ordered today

...Loading

Estimated Ship Date: Jun 29, 2026 if ordered today

FAST Idle Air Control Harness Adapters 308023

Harness Adapter, IAC to FAST EFI, Chevy, Pontiac, Each

Part Number: FST-308023

5.0 out of 5 stars ( 3 )

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

FAST XFI Fuel Injector Harnesses 301203

Wiring Harness, Fuel Injector, FAST XFI, Ford, Each

Part Number: FST-301203

Not Yet Reviewed

Estimated Ship Date: Monday 4/27/2026 if shipped by air

...Loading

Estimated Ship Date: Monday 4/27/2026 if shipped by air

Holley Replacement Fuel Injector Wiring Harnesses 558-500

Fuel Injection System Wiring Harnesses, Holley EFI, GM LS 24X Crank Sensor, Includes Power, LS1 Injector, Main Harnesses, for HP, Dominator ECUs, Kit

Part Number: HLY-558-500

Not Yet Reviewed

Estimated Ship Date: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 2026 if ordered today

FAST Analog Input Kits 301402

HARNESS, FAST ANALOG INPUT KIT

Part Number: FST-301402

Not Yet Reviewed

Estimated Ship Date: Jun 29, 2026 if ordered today

...Loading

Estimated Ship Date: Jun 29, 2026 if ordered today

Holley EFI Systems Main Wiring Harnesses for 2011-2017 F-150, MUSTANG - 558-122

Fuel Injection System Wiring Harnesses, Holley EFI, Coyote Ti-VCT, Main Harness, Plug-and-Play, Drive-by-Wire, with Holley Smart Coils, Ford, 5.0L Kit

Part Number: HLY-558-122

Not Yet Reviewed

Estimated Ship Date: May 13, 2026 if ordered today

...Loading

Estimated Ship Date: May 13, 2026 if ordered today