Help with whistle (noise) between 2k-3k rpm

[tylerSS]

OK guys need a little help....im in process of installing my nitrous outlet plate system....and all i have done so far is remove the engine cover, "clock" the throttle body, install the plate and mounted the solenoids/hard lines......after doing all this i reinstalled the intake and was finished for the day......after all this i get a very distinct whistle between 2k-3k rpms under light throttle.....i thought i may have left an intake clamp loose but double check and they are all tight......anybody have any ideas on what may be causing this or if rotating the throttle body for some reason would make this whistle......any help or ideas will be greatly appreciated.....