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Holley HP EFI ECU & Harness Kit GM LS2/LS3/LS7

Holley 550-603


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Holley HP EFI ECU & Harness Kit GM LS2/LS3/LS7 $1,819.95
HP EFI ECU & Harness Kit
  • GM LS2/LS3/LS7
  • 58 Tooth Crank Sensor
  • Uscar (EV6) Injector Connectors
  • Bosch Oxygen Sensor
  • Uses Factory GM Coil Harnesses

  • Holley 550-603 Details

    ECU & Harness


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    Manufacturer's Part Number:

    Complete 1997-Up GM LS Engine Plug and Play Engine Controller Kit

    Looking for a plug and play kit for your GM LS engine? The HP ECU allows you to accurately control the fuel and ignition of your engine plus much more! Is your cam too wild for a MAF? Power adders? You name it, and Holley EFI can handle it. Kits are not designed to control VVT (Variable Valve Timing) or Drive-by-Wire. VVT should be locked. Dominator ECU is required for drive-by-wire applications. Holley HP EFI systems are equipped with 4 programmable inputs and 4 programmable outputs that are ideal for most vehicles with a single power adder. This feature allows the user to configure the system to support a wide range of controls including boost control, progressive nitrous, water/meth injection, speed inputs, fuel pump control, AC inputs, timing retard inputs and various other uses. When selecting an ECU, users need to ensure their planned controls can be run with the 4 inputs and 4 outputs as certain combinations may use more inputs/outputs than are available. If more inputs/outputs are required, users should choose the Dominator VMS. ECU is certified to ISO 8846, SAE J1171 & United States Coast Guard Requirements for Ignition Protection & Fire Resistance.


    • Designed specifically for 1997-Present GM Gen III and Gen IV LS Style Engines (LS1/LS2/LS3/LS6/LS7)
    • Kits for 24x or 58x Crank Sensor
    • Plug and play with factory sensors; Crank, Cam, Cylinder Head Temp, etc
    • Plug and play with factory actuators; Coils, Injectors
    • Connectors for Holley Fuel Pressure and Oil Pressure sensors
    • Connectors for expanded Inputs and Outputs
    • Complete plug and play kits include HP ECU, Wideband O2 sensor (choice of Bosch or NTK), MAP sensor, Coil Drivers and all necessary Harnesses
    Click here for Holley HP Inline Fuel Pumps
    Click here for Holley Dominator Inline Fuel Pumps

    Some parts are not legal for use in California or other states with similar laws / regulations