HIgh Quality Auto Parts Exhaust TWC Catalyst Direct Fit Catalytic Converter for BMW 320 520

Temperature is very important for catalysts. Only when the appropriate temperature is reached can the rate of chemical reactions be maximized. This is why in automobile exhaust emission testing, the gas collected during cold start is a very important check, because the engine has just started, the exhaust temperature is low, the catalyst activity is low, and pollutants cannot be efficiently converted