Usually, there is a thing called the "exhaust pipe" outside the exhaust drum, which is known to catalyze pollutants in the exhaust gas and make it cleaner. The modified exhaust drum 20 is also located in this position, seriously affecting the exhaust flow rate. Generally, a three-way catalyst is a dense honeycomb structure with 8 to 900 pores (800 mesh and 900 mesh), which can divert exhaust gas and perform sufficient catalysis. To achieve complete catalysis, a sufficient high temperature is required, and the closer the drum is to the exhaust valve, the higher the temperature of the exhaust gas, making it easier to produce significant catalytic effects. Most car manufacturers, in order to meet environmental standards more easily, choose to install the original device near the head of the exhaust valve. But in doing so, the drum can easily hinder the smooth emission of exhaust gas, and even the low rotation back pressure is too high, causing a loss of combustion efficiency.
