ENGINE

摘要

In an exhaust gas-purifying device where a catalyst is provided in an exhaust gas passage (5) of an engine (1), the catalyst is composed of a reduction catalyst (8) provided in the exhaust gas passage (5) and an oxidation catalyst (9) provided in the exhaust gas passage (5), on the down stream side of the reduction catalyst (8). A main secondary air-feeding passage (12a) is connected between the reduction and oxidation catalysts (8, 9) in the exhaust gas passage (5), and an auxiliary air-feeding passage (12b) is connected to the upstream side of the reduction catalyst (8). When the engine is in a cold state, secondary air is fed from the auxiliary air-feeding passage (12b).