The title says it all, I bought the Sneed4Speed catless downpipe the other day and got it installed. For the first couple of days, it sounds wonderful and way loud but I got into my car this morning, and when accelerating it's creating this nasty rasp. I currently have no resonator or muffler, but I'm curious if anyone else has had this problem. Or if it has to do with something that is connecting the downpipe is loose.

 

If it is the downpipe creating the sound i would think the only things it could be is either a weld failed or something came loose like the exhaust clamp.

 

If you have no resonator or muffler, it will be raspy. But regardless, sounds like you have a loose joint somewhere or the exhaust is on the middle subframe.