Unit Inspection

WARNING: This page is about a different car, the 2014 Subaru BRZ. However, it is still accessible from the selected car via links, so may be relevant.

Chamber assembly check
1. Check that air does not comes out easily from the IN side when air is blown into the chamber from the EX side.
  
  Fig 1: Identifying Chamber assembly Exhaust And Intake Side
  Courtesy of SUBARU OF AMERICA, INC.