Originally Posted by iNfEk
Right next tune something that isn't even setup as a base for what you'll be running. It's harder and more expensive. Furthermore. The AVCS mapping isn't on the 03 WRX ROM. furthermore, It also doesn't deal with all the emissions BS. So CELs and such as much of a problem. Buy engine and ECU. get AVCS harness from IAP install. Once the engine gets here you'll need to remove the old and install the new along with the correct ECU.