If someone can give me some info and some symptoms of this failing id appreciate it.. Thanks.

On the Nissans most discussed in these forums it is called the Air Regulator. What kind of car do you have? An air regulator does what the name implies. It opens to allow extra air to enter your engine when it is cold so that the car idles at higher speeds until the engine warms up a bit. Once the engine warms a bit, the air regulator will close and your engine will idle at it's normal speed. When your engine is cold the air regulator remains open. When the engine is started, the air regulator is fed with electrical current, this current in turns heats a bimetallic valve (a valve that closes as it heats up). So the longer you run the engine the more the valve heats up and consequently closes, untils it closes all the way when the engine is warm. If you air regulator is broken or if it is not recieving that current which closes it, it will remain open. And even though your engine may have warmed up, the valve is still open and it will make your engine idle way too high.