Internal Combustion Engine Vehicles or ICEVs play a major role in air pollution for big cities like Tehran. Catalyst converters manage to contain much of the generated pollution from combustion and are considered as a mandatory part of any vehicle. Manufacturer guidelines clarify a certain mileage for catalyst to be regarded as completely degraded and thus unable to contain harmful gasses from combustion. In this paper we test the theory that catalyst degradation is greatly affected by driving condition by using kinematic simulation of vehicle in different driving cycles. Catalyst degradation parameters are derived for the reference driving cycle (NEDC) and then developed accordingly for other driving conditions. The vehicle model with degradation sub-model is then utilized for investigating different scenarios of replacing old catalyst with a new one. Results clearly support the idea that driving cycles greatly affect the degradation age of 3-way catalysts and vehicle emissions are increased up to 5 times by using catalyst after its age limit. For Tehran driving cycle, 75K kilometers appears to be the aging limit. Authors conclude that local investigation of driving cycles is necessary for finding degradation limits and careful designation of parts replacement plans can help to massively increase air quality in large cities.