How to Clean a Car's Three-Way Catalytic Converter?
4 Answers
Methods for cleaning a car's three-way catalytic converter: 1. Use oxalic acid solution for cleaning, which is highly effective. However, this method requires disassembling the three-way catalytic device, and there are specific requirements for the dilution ratio of the oxalic acid solution and soaking time. Improper use may damage the internal structure. 2. Non-disassembly cleaning, which involves "drip cleaning" or adding cleaning agents to the fuel tank. This method is less effective than the first one and is suitable for mild blockages in the three-way catalytic converter. The three-way catalytic converter refers to a catalytic device that converts harmful gases such as CO, HC, and NOx emitted from car exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. The core component of the three-way catalytic converter is a porous ceramic material installed in a specially designed exhaust pipe.
I cleaned my catalytic converter myself recently, and the steps were quite simple—don't be intimidated by the jargon. Just buy a bottle of specialized cleaner, park your car in a safe spot, and turn off the engine. Locate the exhaust pipe connection, insert the cleaner tube into the oxygen sensor port, and start the engine to let the cleaning fluid slowly inject—engine RPM fluctuations are normal. Keep flushing for 10-15 minutes until the can is empty. Remember to wear gloves and a mask, and be careful not to burn yourself as the exhaust pipe gets extremely hot. Doing this once a month can prevent clogging, and you’ll notice significantly better exhaust purification—the car even accelerates more smoothly. If the exhaust still smells pungent afterward, the catalytic converter might be completely damaged and need replacement.
As someone who frequently deals with cars, I believe cleaning the catalytic converter requires attention to detail. First, confirm if it really needs cleaning: symptoms like engine shaking at idle, sudden increase in fuel consumption, or lack of power when climbing hills indicate a blockage. There are two cleaning methods: non-disassembly and disassembly. Beginners can simply pour a non-disassembly cleaner into the exhaust pipe, while experienced individuals can remove it, soak it in oxalic acid solution for half an hour, and then rinse it with a high-pressure water gun. Always operate in a well-ventilated area, as exhaust fumes are toxic. After cleaning, remember to clean the oxygen sensor, otherwise the readings won't be accurate. Professional shops charge a few hundred for this service, but doing it yourself can save over two hundred, though it takes about two hours to do it properly.
Having driven for over a decade, I can tell you that the catalytic converter fears poor fuel quality the most. Don't skimp on gas—using higher-grade gasoline means fewer impurities and less frequent cleanings. The cleaning process isn't complicated: connect the cleaner to the intake manifold vacuum hose, then spray the solution while the engine is running. You'll smell sulfur during the process, which indicates carbon deposits breaking down. After cleaning, take a highway drive to flush out residues. To prolong its lifespan, check the exhaust pipe color every six months—if it's too black, it's time for a cleaning. Also, avoid short trips where the engine doesn't warm up, as the converter clogs more easily. Record the steps on your phone while doing it yourself to make the next attempt smoother.
