What Causes Three-Way Catalytic Converter Failure?
2 Answers
Three-way catalytic converter failure causes: leaded gasoline, lubricants or additives containing lead, silicon, phosphorus, sealants containing harmful components like lead and silicon, overheating, severe impacts, etc. Below are detailed explanations of the related causes: 1. Leaded gasoline: Tetraethyl lead in leaded gasoline causes significant pollution and harm to the environment and human health. It also deposits on the active surfaces of the oxygen sensor and catalytic converter in the catalytic device, leading to 'lead poisoning' of the oxygen sensor and greatly reducing the purification efficiency of the three-way catalytic converter until it is damaged. Long-term use of leaded gasoline can even clog the honeycomb catalytic converter in the catalytic device with tetraethyl lead. 2. Lubricants or additives containing lead, silicon, or phosphorus: Many people assume that if the exhaust pipe doesn't emit blue smoke during engine operation, no lubricant enters the exhaust system. In reality, even a well-functioning engine burns a certain amount of lubricant that passes through the cylinder walls and PCV valve in the combustion chamber. Therefore, harmful components mixed into the lubricant can also cause the three-way catalytic converter to fail if they come into contact with the catalytic conversion device. 3. Sealants containing harmful components like lead and silicon: Engine repairs often require the use of various sealants. However, if sealants containing the aforementioned harmful components are applied to areas such as the intake manifold gasket or oil pan gasket, they can poison or even disable the three-way catalytic converter. 4. Overheating: The operating temperature of a three-way catalytic converter typically should not exceed 800°C. However, if a cylinder in the engine misfires, the exhaust may contain excessive unburned fuel gases, which can cause the three-way catalytic converter to fail or be damaged due to a significant increase in operating temperature. 5. Severe impacts: Since the core of the catalytic converter is a ceramic element, vehicles equipped with three-way catalytic converters are particularly vulnerable to 'bottoming out.' Severe impacts can shatter the catalytic converter core, rendering it useless.
I've been researching car modifications for a while, and there are several common causes of catalytic converter failure. One is poor engine combustion issues, such as spark plug ignition failure or intake system malfunctions, which can lead to unburned gasoline spraying into the converter and clogging its interior. Another is high-temperature damage, where aggressive driving causes excessively high exhaust temperatures that may melt the converter's structure. Physical impact is also a common cause, as potholes or accidental collisions can crack the outer shell. Long-term use and aging are contributing factors too, with metal components corroding or carbon buildup reducing efficiency. These issues can result in decreased vehicle power and illuminated emission warning lights. It's recommended to regularly check the engine's condition and avoid frequent hard acceleration to prevent such problems. When modifying the exhaust system, be cautious in selecting components, as improper choices can make the converter more prone to damage.
