Ive done a search and it seems like some people have had the same problem but the fix was never found and those threads jsut dies.

At first I was sure it was my brakes, simular sound. But when I stop and rev, it is still there.

Some peeps in the car say it sounds like a sharp air leak. Others say it sounds like a belt. It kinda sounds to me like a sharp circular vibrating (like metal rings spinning on a metal stick at a high rate). Can it be my bub? I was thinking a hub is more lower pitched.

Only recent thing Ive done is new header and new cat cause I failed smog the first time. I did visual inspection of these items and they look good as well as checked the hoses.

Please help!?