I was changing my air filter and i noticed there is an alluminum pipe going into the air intake box. There is a divider valve that is closed preventing the air from this pipe going into the engine. Whats this pipe for and is there a reason it would be closed or should it be open??

 

That pipe connects to the exhaust manifold. When the car is cold the valve should be open to get hot air from the exhaust to help the motor warm up faster.