And no a muffler change out will not give you more power.
In fact changing the catback out on these cars is pointless unless your gonna make 500whp
Cry havoc and let slip the dogs of war.
2004 Saab 9-5 Aero - WAHSAABI - Way too much power/Koni FSD & Hirsch Springs/Big Sways - DD/AutoX'r
2007 Ford F-150 Lariat - 5.4L V8 - Bill secretly likes it
2015 Mitsubishi Outlander Sport SE - Wifey Mobile