Method to heat catalytic converter of internal combustion engine after cold start has secondary air channel branching off fresh air channel for vehicle interior and connected to engine exhaust system

摘要

A motor vehicle has a blower (18) with channel (20) to feed fresh air into the vehicle interior (24). A secondary air channel (26) branches off the feed channel downstream of the blower, and is connected to the exhaust system (12,14) of the engine (10) upstream of the catalytic converter (16). The secondary channel is opened and closed selectively by a switching device (30) with flap inside the channel.