A system for controlling a flow of intake air in a secondary intake air passage (16) during a start-up period of an internal combustion engine. A main intake air passage extends to an intake port of the engine (11). A throttle valve (13) is located in the ...

A method and an apparatus for controlling the emission of harmful gases from internal combustion engines (10) fitted with an afterburning catalytic system (24). Primary and secondary air for combustion are fed to the engine (10) by means of a main air-feed...