I am having this horrible rattle that I cant get rid of, which happens when I rev my car at about 3500 rpm or more and let of the throttle. Its hard to describe the noise, but it sounds like a bolt rattling around in the exhaust and when flooring it, like the "bolt" is bouncing around, but im sure its not a bolt. It sounds like a bad metal noise, but not a grinding noise. I have a budget y pipe as my only exhaust mod, and I have removed my cat heat shield, because I read that might be my problem. Nothing has changed after that removal. My friend brought his 95 Nissan Altima over today and said he was having a rattle also, and it turns out its just like mine, but he has no exhaust work. He and I both listened under the car and have determined that it has to be from the cat to y pipe flex area, In between there somwhere. Anybody have any Ideas, It's really starting to **** me off.

Thanks,

-Nick

 

your cat could be going bad and rotting from the inside...... bad kitty

 

Bad flex section in the y-pipe? Only way to know is to remove it and check inside. Might as well check the inside of the cat while you are at it.

 

bees in a can sound

 

It's a not bees in a can sound. Any other ideas?

 

My y-pipe rattled too (Stillen)...it went away, but from what I can see, it was the bracket rattling against the bottom of the engine.

Now that I think of it, mine wasn't really a rattle as much as a banging noise. Get a drop-light and look under the car while someone hits the gas. See if anything is moving.

 

What bracket? Can you be more specific.

 

It was a metal bracket that was welded to the pipe (maybe budget doesn't have one). It almost matched up with a threaded hole on the bottom of the engine (did my mechanic forget to bolt it down?).