Tuneless connects to your ECU over a CAN-to-USB cable — it doesn't come in the box with the ECU, and Holley uses two different connectors across its EFI lineup. Match your connector below and get the right one before you start.
Look at the cable end of your handheld touchscreen display and match it to one of the two connectors photographed above.
Every other Holley EFI — Sniper 1, Terminator X, and Dominator all share this flat connector with red and black leads.
Get part 558-443 →Not sure which ECU you have, or the connector doesn't match either photo? Email hello@tuneless.tech with a photo of your harness and we'll confirm which cable to order.