The present invention relates to an apparatus for so as to continuously maintain the performance of automotive catalytic converter, the exhaust manifold and the exhaust short passage and the exhaust long passage formed in parallel to the catalytic converter, both of the exhaust short passage and the exhaust long pathway receiving a variable valve means provided in the exhaust manifold-side connecting portions of the connecting portion and the exhaust manifold and the signal of the variable exhaust gas temperature sensor is installed between the installation of the valve means position, the exhaust gas temperature sensor to the ECU that the operation of the variable valve means by providing the catalytic performance of the holding device consisting of car, by continuously maintaining the smooth state of the catalytic converter it can contribute to eliminate the harmful components of exhaust gases.