I just hit a small deer last night with my 01 stratus, cracked my bumper. But on the front left side it makes a faint whistling noise. My radiator isnt leaking. Check engine light was not on. And tonoght I had my dad look at it and claims he couldn't hear it. Also there was a blue sensor looking thing that was unplugged by the intake tube thing, and he tried to plug it in a hole that had an arrow on it and broke the little blue sensor off but not the plug in. Now the check engine ligght is on and the car is louder. Wtf could this be?
Can you post a photo of the part? It sounds like an ambient air temperature sensor. That will have two wires going to it. Since the Check Engine light turned on there is going to be a diagnostic fault code set in the Engine Computer. Cycle the ignition switch three times from "off" to "run" within five seconds, leave it on, and watch the code numbers show up in the odometer display.