A reliability analysis was conducted by means of the failure mode effect analysis technique on the catalytic converter which has been adopted in the 1975 Toyota models. A series of vehicle tests was conducted to determine the failure modes criticality. The study was performed on a precious metal pelleted catalyst. Critical durability failure modes to the durability of the catalytic converter and their criticality were classified and substantiated through this study. The results are presented and discussed.The results obtained by this analysis are useful for improving the reliability of the catalytic converter.