quick view Add to Cart FAST FAST Wiring Harness FAST Main - 301100 MSRP: $831.99 FAST offers several main harness options to aC-Commodate most customers' needs. The XFI Main Harness is responsible for connecting your XFI ECU to sensors as well as digital dashes, EGT modules, and various optional accessories. The Main Harness also... Add to Cart Add to Wish List Add to My Wish List Create New Wish List Compare