CO emission is one of biggest problem in environmental sector due to increasing number of motorcycle user in every years. CO is poison gas which directly affects on the public health and earth’s atmosphere. The aim of this research to developed catalyst in catalytic converter system to oxidize CO to CO2 by using MnO2/zeolite NaY. Zeolite NaY was synthesized by using hydrothermal method following by wet impregnation to form MnO2/zeolite NaY, then the composite was characterized by XRD, FTIR, SEM-EDX, N2 physisorption, and catalytic activity oxidation of CO was carried out using 4 tag motorcycle. The XRD result represent zeolite NaY synthetic has similar diffraction peak with zeolite NaY (JCPDS 39-1380), then infrared spectrum exhibit T-O-T at fingerprint area which exhibit vibration of zeolite NaY. Octahedral crystal was successfully observe by using SEM which represent zeolite NaY crystal similar with previous study. N2 physisorp shows that the composite has type IV of isotherm which exhibit the micropore and mesopore was form into material. Then, MnO2/zeolite NaY has good thermal stability as well as catalytic activity for CO oxidation, where the longer reaction time successfully to reduce the concentration of CO. Conversely, CO2 concentration dramatically increase as function of reaction time.