This EJ205 also has the AVCS choice to operate for additional overall performance. To run the AVCS, the avcs harness along with the avcs ecu is required. Even so, That is optional, you don’t have to run the avcs to generate the motor healthy within your 2002 to 2005 WRX. It is just a immediate very long block substitution for 2002 to 2005 Subaru