Buzzing/whistling from car?

Alright so my car has been making this annoying whistling/buzzing sound for a while, and I finally got sick of it. The car is a 99 Eclipse GS, which has the 4 cylinder 420a engine. It has a (Supposedly) Megan exhaust, but knowing the previous owner, it could be welded together soda cans for all I know. Anyways, I originally thought it was an exhaust leak making the sound but it only happens when press on the gas a certain amount; about 40%. For example, If I'm taking off from a stop and accelerate hard, it will buzz/whistle but I can redline it by pressing more gently and getting to redline more slowly and it won't do it at all, so my thought is something with the throttle body. I also have an AEM short ram intake on it, and the cone filter is kind of loose, and I can't seem to get it to stay tight. Could replacing the filter fix the noise? I've been sick the past few days and the loud exhaust doesn't bother me but that whistle/buzz is making my head hurt even worse, so any ideas are appreciated, thank you.