What is inside a three-way catalytic converter?
3 Answers
A three-way catalytic converter contains three precious metals: platinum (Pt), rhodium (Rh), and palladium (Pd). It is called "three-way" because these three precious metals facilitate the reaction of the three main harmful gases produced after engine combustion, ultimately converting them into harmless carbon dioxide, nitrogen dioxide, and water. The three-way catalytic converter is a crucial external purification device in a car's exhaust system. Its primary function is to convert harmful gases emitted by the engine into harmless ones. The three-way catalytic converter is located in the first section of the car's exhaust pipe and resembles a canteen in shape. It is equipped with an oxygen sensor. If removed, it will affect the closed-loop control of oxygen concentration, thereby impacting fuel injection control and throttle opening, polluting the environment, and causing the vehicle to fail the emissions test during annual inspections.
The three-way catalytic converter mainly contains several precious metal catalysts, with the core ones being platinum, palladium, and rhodium. These are coated onto a honeycomb-shaped ceramic substrate. Its function is to convert harmful gases in the exhaust, such as carbon monoxide, hydrocarbons, and nitrogen oxides, into harmless water vapor, carbon dioxide, and nitrogen. From what I understand, if the catalytic converter is damaged—possibly due to excessive carbon buildup or overheating—it can lead to excessive vehicle emissions or increased fuel consumption. When driving normally, it's best to regularly check the exhaust system, avoid using low-quality gasoline, and prevent abnormal engine operation from impacting it. This way, you can extend its lifespan and maintain its environmental performance. If the exhaust smell becomes unusual or the engine light comes on, you should promptly visit a repair shop for inspection.
The core of the catalytic converter consists of several rare metal coatings, including platinum and palladium, which are used to purify exhaust gases. I've noticed that many long-time car owners neglect maintenance, leading to clogging or failure of the converter. This could be due to prolonged short-distance city driving where incomplete fuel combustion generates carbon deposits, or the use of fuel containing impurities. Prevention is simple: regularly drive at high speeds to clear carbon buildup; use higher-quality engine oil; and don't overlook exhaust inspections during car washes. If the catalytic converter fails, the car may shake and fuel consumption can skyrocket. In such cases, professional diagnosis and replacement are necessary—otherwise, the car won't pass emissions inspections and will end up costing more in the long run.
