Bolted directly to the engine block, the exhaust manifold is the first section of a vehicle’s exhaust system. It funnels exhaust gases from all the cylinders and routes them to the car’s catalytic converter. V-type engines have a separate manifold for each cylinder bank.
A leak in the exhaust manifold or its gasket can allow exhaust gases to escape, which poses a health hazard to the car’s occupants and can result in erroneous readings by the oxygen sensor, triggering a check engine light. Larger holes in a manifold will produce loud exhaust noise.