I found this on the Walker site. It says 2" in and 2" out. This muffler is a direct replacement for the 2004 Alero. Has anyone tried this? Just wondering how it sounds.
http://www.walkerexhaust.com/catalog...g-lookup/18557
Muffler Inlet Count 1
Muffler Inlet Diameter 1 2.000"
Muffler Inlet Diameter Designation Outside Diameter
Muffler Inlet Connection Type Pipe Connection
Muffler Outlet Configuration Offset
Muffler Outlet Count 2
Muffler Outlet Diameter 2.000"