chirping noise on 2000 taurus while idling

I have a 2000 taurus ...While idling, it has a chirping noise in the area near throttle body. sound does not increase with acceleration it actually dissappears. generally happens after engine has warmed up. Any ideas of what's going on here?...(sounds a little like belt noise)

You sure it's not more of a ticking noise? Sometimes the injectors can be a bit noisy.

No, not a ticking noise....sounds like it could be belt noise..but that has been eliminated...(new belt) and noise is away from belts....Someone suggested it may be Cam Sensor......and I heard that egr valve made some noises....but it doesn't sosund like a whisle or air noise. Thanks.