Is Washing the Three-Way Catalytic Converter Useful?
2 Answers
Washing the three-way catalytic converter is not useful. The three-way catalytic converter does not need frequent cleaning. If the oxidation of the three-way catalytic converter is severe, it should be replaced directly. The operating temperature of the three-way catalytic converter is around 350 degrees Celsius, and there should be no residual liquid water, so cleaning is not advisable. The working principle of the three-way catalytic converter is: when high-temperature exhaust gases pass through the purification device, the purifying agents in the three-way catalytic converter enhance the activity of CO, HC, and NOx gases, promoting certain oxidation-reduction chemical reactions. The methods for cleaning the three-way catalytic converter are: 1. Add cleaning agents to the fuel tank; 2. Use the vacuum suction of the intake system to perform a hanging bottle cleaning, drawing the cleaning agent into the combustion chamber for burning, achieving the purpose of restoring the activity of the three-way catalytic converter through oxidation-reduction reactions inside it; 3. Remove the three-way catalytic converter and soak it in oxalic acid and toilet cleaner, then rinse it with clean water.
I've been running an auto repair shop for nearly a decade, and I often see people trying to save money and effort by washing their catalytic converters with water, but this method is basically useless. The inside of a catalytic converter is coated with ceramic catalyst materials, and water washing can damage this coating, leading to clogging or corrosion, which can cause even bigger problems. Catalytic converter failures are usually caused by excessive carbon buildup, lead poisoning, or physical damage, none of which can be fixed by washing with water. Adding fuel additives might help clean carbon deposits, but washing with water only makes things worse. If you notice unusual exhaust odors or the engine light comes on, don't attempt to wash it randomly—it's best to use professional cleaning tools or have it checked at a reliable repair shop. A failed catalytic converter will cause excessive emissions, making it impossible to pass annual inspections, and long-term neglect will only increase repair costs. Remember to use high-quality fuel and avoid short trips to reduce carbon buildup.
