This EJ205 also has the AVCS option to run For extra efficiency. To operate the AVCS, the avcs harness as well as the avcs ecu is necessary. Even so, This is often optional, you don’t really need to operate the avcs to produce the motor in shape in your 2002 to 2005 WRX. This is a direct extensive block substitute for 2002 to 2005 Subaru WRX.For