Since getting the zzp longtube header with 2.5" catted downpipe I thought the stock ls catback needed replacing too.
I just put on the catback from a cobalt ss/sc, needed some tweaking as it was hitting at the top of the axle hump, and tip had a dropdown extension that had to be cut off.
Its much bigger in diameter and the longer resonator gives a deeper note.
Overall im really happy with the result, and I would recommend this cheap mod for the sound alone, should help performance a bit too.
http://www.youtube.com/watch?v=dnb-6udOyug

 

Sounds good! Since sound is really all you get out of changing up the exhaust on these wagons, I'm still thinking a cheap aftermarket muffler is going to be more cost effective.

What kind of sound did you get with the factory exhaust with the ZZP longtube?

 

the header with stock catback sounded nice, but now its deeper and louder.
Now that I have intake and exhaust done, as soon as I have a chance I will start on the supercharger, finally have all the parts (I hope lol). Unfortunately I am in the middle of moving, so that will have to wait a bit.

 

I'm going to the muffler shop tomorrow to see what they can set me up with...I cant wait any longer...gotta have some sound!