4th Gen F Body Plug-and-Play LSX Harness for Holley EFI

  • Sale
  • Regular price $1,164.95

Back by popular demand with a clean slate redesign! These systems are built to order, with a lead time of 3-5 weeks. Please make note of lead time, or contact us with any questions before ordering. Thank you!

If you're looking to take your 4th gen Camaro or Trans Am street car to the next level with Holley EFI, we have your solution.

  • Intended for mild to moderate street cars that have hit limitations of a stock PCM.
  • Available for Haltech Elite, Holley HP, Dominator and Terminator X ECU's
  • Available for both LS and LT cars
  • Seamlessly plug-and-play with factory body connections
  • Retains full use of factory fuse and relay centers
  • Terminated alternator lead built-in
  • Plug-and-play to keep factory gauge cluster functional*
  • Factory traction control switch pinned to an input for custom function (as applicable for model year).
  • CAN bus connection fed inside cabin with gauge connections

Piggybacking Stock PCM

  • The stock gauge cluster on 99-02 cars will NOT function without piggybacking a factory PCM.
  • The stock gauge cluster on 93-98 cars can be made to function without piggybacking a factory PCM, but will require sacrificing some I/O from the Holley ECU.
  • Harness is laid out to keep factory PCM in stock location, in RH rear corner of engine bay.
  • Factory PCM is left in control of mundane factory functions:
    • Radiator fans
    • Factory A/C control
    • Manual transmission functions
  • Holley / Haltech ECU is in full control of fuel, spark & automatic transmission controls (as applicable).
  • HPTuners / EFI Live license required to disable all applicable codes for functions no longer pinned into factory PCM.
  • Piggybacking the stock PCM is NOT intended for keeping a car emissions compliant, and WILL NOT keep a car emissions compliant in states that require smog testing.

I/O Loadout

  • The harness features a "stub" connector at the RH rear corner of the engine bay, pinned with the following for easy access and wiring:
    • 4x aux inputs
    • 4x aux outputs
    • Sensor 5v reference
    • Sensor ground
    • Low current fused 12v
    • Chassis ground
  • Auxiliary I/O on the aftermarket ECU are used for functions such as auxiliary sensors and race functions:
    • Boost control
    • Nitrous control
    • Flex fuel
    • Trans brake / 2 step
    • Auxiliary pressure & temperature sensors
  • Auxiliary I/O can be used for fan control, A/C control, etc rather than opting to piggyback a stock PCM, but options for additional functions may then be limited.