You could always get a single port exhaust, and get a double tip from pacesetter, or monza... lol They are pretty nice, and not ricey... I have been looking for some kind of muffler, that might free up a little HP, and give me that minor boost I need. It's definitely not an easy thing to find...
You best bet with that is to do as Joe did- He grabbed another Cat and is using it to smog- I dont know if he is going to gut the orignal on, But you should be able to get 1-2 Xtra HP....
I was also looking for a throaty response from the exhaust also... I feel that the stock muffler doesn't allow it to sound the way it should... lol I don't want that rice like whine, just a lower tone... You know what I mean?
I had a str8 exhaust to a stock gts muffler which sounded sweet.. so what im gonna do is take the cat back off and put back my str8 pipe back on. heres mine when is was a little crooked lolol along time ago
my car doest have the cat just a little muffler in between , but yeah id rather just have that taken out and straight pipe to muffler , but without getting ahead of my self only a couple of days b4 i take it to the mechanics for the bottom ends !! i miss it soo much poor thing is stuck down at work parked next to my sisters busted nissan exa lol