Catalytic converter heater control system for internal combustion engine

摘要

A catalytic converter heater control system for an internal combustion engine comprising a catalytic converter installed in the engine exhaust gas passage and having a small capacity section on its upstream side and a large capacity section on its downstream side. The system has a pair of oxygen sensors installed one on the upstream side and one on the downstream side of the catalytic converter, a heater installed on the small capacity reaction section for heating incoming exhaust gas, and an electronic control unit for operating the heater when the difference between the outputs of the oxygen sensors is smaller than a prescribed value.