This EJ205 also has the AVCS option to run For added overall performance. To run the AVCS, the avcs harness plus the avcs ecu is necessary. Nonetheless, This is often optional, you don’t must run the avcs for making the motor healthy within your 2002 to 2005 WRX. This is a direct extended block substitute for 2002 to 2005 Subaru WRX.?????????????