I have no intention on changing the exhaust to make it louder, I don't enjoy the exhaust note of 4 cylinders very much.

From what I understand the 07+ comes with the "upgraded header" from the Supercharged cars. My question is would there be flow gains from the DP? I am hesitant to touch the cat back because of the sound.

Thoughts,

John

I can speak for the catback. Like you, I'm not a fan of the ricey sound, and I have yet to hear a 4cyl I like (MAYBE an sti, MAYBE...). About a year ago I bought the GMPP touring exhaust and absolutely love it! The sound is really nice, its very quiet, but deep and smooth sounding. I can't complain one bit. If anything I think its too quiet. I gained 3mpg from the exhaust.

As for the header, I have my doubts. It is a larger diameter, in a low flowing engine that is only going to hurt performance and efficiency. Maybe someone out there will be able to offer first hand experience.

Search youtube and see if you can find a cobalt with the gmpp touring exhaust, listen and see what you think.

The header I have, all 07+ 2.2s came with the larger header. I am wondering about upgrading the DP to match as the DP is still the same 2.2 DP they have had.

Touring is the quieter of the 2 GM options? Might have to consider it then.

I wonder what a stock SC catback would do?