Ok so I started getting a really bad rattle in my exhaust system around my Vibrant High Flow Cat. As most of you have read, my car has always sounded like SHIT. Well the rattle got real bad and goign down the road my car got quieter/deeper sounding. It sounded great! The tone was deep and not to loud, yet rumbled when I got on it hard. Well I went to a local mineke(sp?) and had it checked out. They said that my cat. catylist(sp?) was broken off inside the cat, and it was what was making the rattle in the exhaust, I loved the sound of the car. But for some od reason after riding my car hard all day the sound suddenly went AWAY AND It came back to sounding like shit!

My question is, why and how would that make my car sound like it did? I had a little bottem end loss while it was like this(lasted around 2 hours). I told them i had a stock cat and a test pipe at my house and they said all they could do is make some flanges and weld on the exhaust for them and I would have to install them myself due to laws. Im going back to stock, but like I said, Hhy did my car tone change so much while the rattle was there, and how did it go away? If something was broken in the cat, it cant magically fix itself???

No, it can't "magically" fix itself but you might have hit a bump and the loose part got wedged somewhere causing the rattle to go away. Then a few hours later, it wiggled free or became un-wedged when you hit a bump and your rattle came back. That would make the most sense to me.

Originally posted by Murfsmaster
No, it can't "magically" fix itself but you might have hit a bump and the loose part got wedged somewhere causing the rattle to go away. Then a few hours later, it wiggled free or became un-wedged when you hit a bump and your rattle came back. That would make the most sense to me.

If that is the only location the noise is coming from, then I also agree.

yes, only place its comming frtom, we lifted the car up on those lifts while running and it was only comnming from there.