A pollutant reducing exhaust manifold for an internal combustion engine incorporating a catalytic converter therein. The manifold has a plurality of header pipes connected to and receiving exhaust gases from respective ones of a plurality of exhaust ports of an internal combustion engine. The header pipes are connected to a single chamber with an outlet therefrom connected to an exhaust pipe as well as a catalytic converter structure having a catalyst disposed on a supporting substrate disposed in the chamber between the inlet(s) and the outlet so that all exhaust gases from the engine must pass through the catalytic converter structure. The catalytic converter operates at higher temperatures for increased efficiency and comes to operating temperature virtually immediately.