EXHAUST GAS PURIFIER FOR ENGINE

PURPOSE:To improve degradation of exhaust gas purifying performance by outputting a correction signal corresponding to the control delay of secondary air in the transferring direction of operating condition of an engine when the operating condition of engine transfers to a region having different supply quantity of secondary air. CONSTITUTION:A catalytic device 3 is arranged in an exhaust path 2 of an engine 1 while a secondary air supply path 5 is coupled to the upstream side thereof and the upstream end of the secondary air supply path 5 is coupled to an intake path 6. Here, an operating condition detecting means 7 detects the operating condition of the engine 1 and modifies secondary air supply quantity through a secondary and modifying means 8 in accordance with said detection result. Furthermore, quantity of fuel being injected from a fuel injection valve 9 arranged in the intake path 6 is controlled through a fuel supply means 10 in accordance with the operating condition of the engine 1. When the engine 1 transfers to an operating condition having different secondary air supply, a correction signal corresponding to the control delay of secondary air in said transferring direction is outputted from a correction means 11 to the fuel supply means 10.