What Causes the Popping Sound from the Exhaust Pipe When Letting Off the Throttle?

[LucyLynn]

The popping sound from the exhaust pipe when letting off the throttle can be caused by various reasons, including aging of the exhaust pipe, malfunction of the car's three-way catalytic converter, issues with the ignition system, or abnormal concentration of the air-fuel mixture. The specific causes are as follows: Aging of the Exhaust Pipe: When a car is too old, the exhaust pipe is prone to aging, which can lead to loosening, detachment, or holes, ultimately causing abnormal noises from the exhaust pipe. This issue is relatively simple to resolve—just re-secure or replace the exhaust pipe. Malfunction of the Car's Three-Way Catalytic Converter: If the three-way catalytic converter malfunctions, it cannot properly purify exhaust gases, leading to blockages and pressure buildup inside, which causes abnormal noises from the exhaust pipe. In this case, it is necessary to visit a repair shop or a 4S store for professional inspection and repair.