Patent ID: 6892527

Claim:
A catalyst deterioration suppressing apparatus that suppresses deterioration of an exhaust purifying catalyst which purifies toxic substances in exhaust gas emitted from an engine, comprising: a catalyst temperature estimating element that estimates a temperature of the catalyst based on a catalyst temperature status, said catalyst temperature status indicating whether the catalyst temperature is increasing or decreasing; a fuel supply stopping element that stops supply of fuel to the engine during deceleration; a fuel supply stop prohibiting element operable when said catalyst temperature estimating element determines that the temperature of the catalyst lies in a high temperature range equal to or greater than a predetermined temperature, for prohibiting said fuel supply stopping element from stopping the supply of fuel; an air-fuel ratio control element that feedback-controls an air-fuel ratio such that the air-fuel ratio is equal to a target air-fuel ratio set based on an operative state of the engine; and a feedback control prohibiting element operable when said fuel supply stop prohibiting element prohibits the supply of fuel from being stopped, for prohibiting said air-fuel ratio control element from providing feedback control.