Honda Element owners are highly recommended to replace their exhaust hanger when installing a MILLERCAT Cat Shield. Over time, rubber exhaust hangers lose their ability to keep the exhaust system from swaying. By replacing your exhaust hanger, you ensure minimal movement of the exhaust and mitigate possible touching with the shield.
If you just a replaced your catalytic converter your exhaust hanger may be fine. It is better to confirm whether you have a new one or not when discussing with your installer. It is not possible to know if the exhaust hanger is good or not just by looking at it.