Noticed today when I had my windows rolled down that I get this whizzing/clunking noise accompanied by some minor vibration coming from around the catalytic converter around 1500-2000 rpms. Anyone know what it can be?

Thanks

 

Were you turning, braking or anything else while you heard this noise?????

 

Nope, can hear it slightly in idle, and when I accelerate it becomes noticible between 1500-2000 rpm. From inside the car with the windows up, you only feel a slight vibration in the chasis, but with the windows down you hear like a metal on metal friction sort of sound in that rpm range at cruising speed and during acceleration.