Originally Posted by jthatch12
Is an 02 ECU plug and play with 04? My initial thought would be no. The flash block isn't even similar. The 03 and 04 ECU flash blocks are identical. I'm not an expert at this but this would be my initial question OP
I think it should be but I've been wanting to confirm this myself. The 03 WRX's use the same 4 pin flash plug that 04/05 WRX's use but all the 03's I've encountered have ECU's that identify as 02 WRX.