Im suprised that you people are telling him to adjust stuff cause of the sounds of his intake. His intake is making the normal sounds.
I have heard some intakes at idle and they sound like a turbo spooling. Some sound like a sucking noise constant
The sounds that your hearing are completly normal.
I ask because I've ridden in a Maxima, and Eclipse, and a Ford Thunderbird with aftermarket intakes and none of them made this whistle sound.
Maximas have bigger engines, they make a roaring sound (sounds great)
Eclipse, if it was turbo the intake dont make noise. I have a CAI on my car and it doesnt make any noise. It does make that whoosh/deep noise right when i hit the gas hard. but it only makes it right when i hit the gas.
Thunderbird's...... dont know what engine but its not going to sound anything like your I4.
All engines sound different