Why is there an explosion inside the car when driving?

This is usually caused by the explosion of exhaust gas from the exhaust pipe. Due to insufficient combustion, some gasoline is discharged to the exhaust pipe, and then ignited again by the high-temperature gas of the engine, so the explosion will have the consequences of explosion. Knocking may be caused by impurities in the fuel, or by adding high-grade gasoline but low-grade gasoline, and too much carbon is deposited in the throttle. Need to add fuel additives, clean the nozzle and throttle to avoid car knocking. In fact, knocking is an abnormal combustion phenomenon, which leads to abnormal combustion chamber pressure. During compression, oil and gas spontaneously combust due to incomplete combustion at high temperature or high pressure. The damage to the engine is relatively large, and the most obvious symptom is that there will be crackling and continuous clicking when driving. Million car purchase subsidy