Okay guys. I am just getting into tuners and need some help. I just got my 09 cobalt ss and would like and exhaust, but have found most of the cat backs are in the 600-700 range. I have found a few mufflers that I would like to try on it that would all be much cheaper. Most are under 100. I looked and it looks like the cobalt already has stainless piping so how well would just replacing the muffle for a much higher flow work, or should I just save up for the full 3" catback?