So I have recently heard a metal high pitched tinny (if that is even a word) noise at around 3000-3400 rpm. I have a hunch that it may be the a-pipe, (lower portion of the header). I have found THROUGH SEARCHING THIS FORUM, that this is a common problem. Does anyone have a suggestion of how I might determine that this is indeed the culprit, before I take it anywhere and pay through the nose to get it fixed. Engine is a B18C1, with oem header.

Thanks,
RWFF