S2000 Upgrades ECU Harness | Performance Upgrades for Automotive Applications. Take a look at the ECU Harness we sell from top brands including AEM and Greddy. We sell ECU Harness for vehicles including Honda. We offer ECU Harness for applications including Honda S2000 and more. Select your vehicle from the search filter below to view ECU Harness by vehicle make, model and year.