A vehicle's exhaust manifold plays the leading role in a car or truck's exhaust system. It connects to each exhaust port on the engine's cylinder head, and it funnels the hot exhaust down into one simple exhaust pipe. With the help of the exhaust manifold gaskets, it also prevents the toxic exhaust fumes from sneaking into the vehicle and harming the occupants. Needless to say, it's pretty important to have your exhaust manifold in good working order.