weird engine noise

[Hmgbobby]

hiya, whenever i rev my engine while in neutral or first gear into the higher rpms, say around 3k and up there is a strange noise.it kinda sounds like a nasty sounding civic with the winey rice sound, i have no idea where its coming from and has just started happening.

plz help with any ideas or comments

[ddgsxr504]

do you have an aftermarket exhaust? Sounds to me like its the heat shield under your seat or the one by the firewall is loose or rattling. I had the same problem with my 95 but i removed all of the heat shields because I run a hotshot header, test pipe and a 3" apexi N1 ehaust.