you're stock muffler may have rotted out if you left it off for a while (my stock one did).

i had custom 2.25" from my cat to an n1 style muffler. that shit was soooo annoying and loud. i switched to a brospeed catback, $225 new. it sounds just like a greddy sp, and i gained A LOT of low end power with the more restrictive exhaust