i know that i posted sumthing similar to this before but its a little different
ok so i have the vibrant dual exhaust, pacesetter header, 2.5 inch pipe, and no cat(i took out the whole thing and replaced it with some good flex pipe)...no i finally took it around the block today for a quick spin, and it sounds horrible.....when it idles its awsome... but when you get it to about 2500 rpms and higher, it sounds like a weed whacker, but really loud......before on my other car i only had the muffler, but the stock manifold and the cat, i could hear it then but it wasnt this nearly this bad....what im wondering is will this sound eventually go away when it all gets broken in, or is it gonna be like this permanently????...unless that sound goes away, i dont plan on driving it around too much without a different muffler....i mean its hideous..sounds like a louder honda with a hole in the muffler

 

Its the cat. Mine totally changed sound too when I put my header on.

 

so it needs a cat???

 

I have Kirk racing header, and pacesetter exhuast without a cat and mine sounds good. I would say get a high flow cat, or a different muffler.

 

i suppose that i could get a cat because i definentaly do not wanna get a new muffler..this one cost enough money

 

when i cut my cat out and used flex pipe it sucked because i had an exhaust leak out of the flex pipe like crazy, then when i had a straight pipe welded in place of the cat it sounded alright, if you put a resonator in you should be alright, mine sounds freakin mean now with the resonator. if i get a better camera to record some of my sound i will show you how mean it sounds

 

so what would be a good resonator...i found a megan racing one on ebay for 60.00 shipped

 

i went to an exhaust shop and they did me up nice for 25 installed