Air leak or intake probs??

Hi all, I am new to this forum, looks like a good place for advice I have an 2002 GT with aprox. 16,189 miles. About a 2 weeks ago, I've been hearing a sound coming from my intake area( Like a squealing or whistling sound). I have lost some power and MPG also with this leak, I do believe its a leak ? My car is a little more fumey now also, I assume I'm running rich.. Last week, my check engine light came on, and it shows the " Idle air control valve" is faulty. They didn't have it in stock, so I had the codes re-set. The engine light hasn't came back on, so I'm not sure its it now?? I have sprayed carb cleaner around to see if I get any idle jumps, and none of course... I have been told I have an intake leak by an auto place by the way he listened to the sound my car is making. Can an intake gasket go bad allready?? I'm out of ideas guys, plus I'm laid off from work. I really can't take it to Ford to charge me $ 80 an hour !@#$% lol My warranty is expired also. So if any1 has any ideas, please feel free.


Thanks all!!

I have an trick flow also. I never had this sound before. I checked everything also. I could go out an buy an IAC, but it cost around $80. 4.6, how long have u had ur whistling sound?