So I have a 2011 WRX running Cobb's OTS stage 1 91 + SF map. I really want to reach stage 2 levels before starting on suspension stuff. Anyways I am wondering if I get a catted Invidia DP, if it is safe to run the OTS stage 2 map from Cobb. In the notes it says you need a full turbo-back exhaust but I have seen people say CBEs change hardly anything except for sound. This being said, would a DP add more of that lovely subie rumble and would it be safe to run with the OTS stage 2 map. BTW I would plan on getting the Q300 around June.