An exhaust manifold is a component of a vehicles exhaust system that collects exhaust gases from multiple cylinders and directs them into one pipe. It is bolted directly to the engine block and is the first section of the exhaust system. The manifold funnels exhaust gases from all the cylinders and routes them to the cars catalytic converter. V-type engines have a separate manifold for each cylinder bank, while inline or straight engines have only one manifold located between the engine cylinder head and the catalytic converter. Exhaust manifolds are generally simple cast iron or stainless steel units that undergo extreme, constant stress with temperature changes under the hood. They can be coated with a ceramic-type finish or heat-resistant finish for customization. Aftermarket tubular exhaust manifolds known as headers can also be added to improve performance. An exhaust manifold leak can cause strange noises coming from the engine, reduced fuel economy, or even dangerous exhaust fumes in the cars cabin.