I was checking for the transmission leak on my car and I noticed that a plug was disconnected from the left top air box. It's right next door to the coolant thermostat. Off or On, the plug did not affect my car's performance at all!! What does it do?

If it didn't affect performance, it's because it's burnt out.

IAT sensor, VERY important.

You're my man, 50 grand.

Thank you; just ordered part.

Edit:

Is the "Air Charge sensor" and "Intake Air Temp Sensor" the same thing?

Yes