What Causes Abnormal Noise in the Three-Way Catalytic Converter?
2 Answers
Abnormal noise in the three-way catalytic converter is caused by a damaged casing or filter. Below are specific details about the three-way catalytic converter: 1. Function: The three-way catalytic converter is a purification device in the engine. Whether it functions properly determines the engine's fuel consumption, power, emissions, and other operational states. 2. Symptoms of Failure: If it becomes clogged or fails, the vehicle's exhaust emissions will exceed standards, and the engine's performance may be affected. Common symptoms include increased fuel consumption, sluggish acceleration, abnormal noise from the exhaust pipe, and unpleasant exhaust odors. 3. Cleaning Interval: Typically, the three-way catalytic converter should be cleaned every 30,000 kilometers. It is also advisable to clean it before an annual vehicle inspection to ensure passing the emissions test smoothly.
I've encountered the issue of catalytic converter rattling several times, and that clicking or buzzing sound is definitely not a good sign. The most common cause is the ceramic honeycomb substrate inside breaking apart, with the fragments colliding inside when driving over bumps. Last time my friend's car had this issue, we took it apart and found the interior completely cracked. It could also be the outer shell rusting through, causing the exhaust pipe's thermal expansion and contraction to deform the metal, leading to contact with the inner lining and noise. Loose mounting brackets are particularly annoying too, rattling with even the slightest chassis vibration. For older cars, the entire converter's hangers aging can also cause rattling. The most dangerous is the sound of clattering fragments, indicating the substrate is completely shattered, which can severely block the exhaust pipe in extreme cases. If you hear any rattling, don't ignore it—get it checked immediately, or you might end up stranded on the road.
