Ok, I get home from work yesterday, back into the driveway and all of the sudden my car starts making this kind of flapping noise from the exhaust I reved it a couple times and noticed its at its worst at about 2000, I got my girlfriend to sit in the car and rev it to about 2500 for me while i was behind the car and i can only hear this flapping sound from the right pipe...Could it be a bad converter or something?? Car seems to run fine but its got a pretty bad smell to it (like a new catt)

 

Sounds like a hole in the exhaust somewhere. Get it up in the air and look at it.

 

mine did that when i had true dual pipes and i mean no H or X just two pipes. Sounded like a plastic bag in the pipe. What kinda set up you got? If it's Y pipe and no muffler it's gotta be either a cat or a hole in the exhaust. If you got a muffler check it out too. I have no idea though. Post something when u find out. I'm curious.

 

I Have the stock Y Pipe into a Borla cat back (the one with the split at the end) w/ the wide open plate in it. I'm going to get under there tonight or tomorrow and see if I can find anything

 

I thought it was supposed to sound like complete crap through the wide open side, mine always did.