Is It Useful to Flush the Three-Way Catalytic Converter with Water?
2 Answers
Flushing the three-way catalytic converter with water is not effective; specialized three-way catalytic converter cleaning agents should be used for cleaning. The three-way catalytic converter is an important external purification device installed in the automotive exhaust system, which converts harmful gases such as CO, HC, and NOx emitted from vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. Since fuel contains harmful substances like sulfur and phosphorus, chemical complexes can form on the surface of the oxygen sensor and inside the three-way catalytic converter after combustion. Additionally, due to poor driving habits or prolonged driving in congested areas, the engine often operates in an incomplete combustion state, leading to carbon deposits in the oxygen sensor and three-way catalytic converter. Therefore, regular cleaning of the three-way catalytic converter is necessary.
When I was young and just bought my first car, I was full of curiosity. I heard that a clogged catalytic converter could drag down performance, so I wondered if I could wash away the carbon deposits like cleaning a car. Last summer, I tried it—right after rinsing it with water, the engine warning light started flashing wildly. When I started the car, thick white smoke poured from the exhaust, and it broke down on the roadside not long after. The mechanic took it apart and found the ceramic inside the catalytic converter had shattered into pieces. Turns out, this thing operates at temperatures as high as 500-600°C, and cold water hitting it is like pouring ice water on hot glass—instant explosion. Replacing the catalytic converter cost me over 3,000 RMB, which hurt like hell. Later, I learned that carbon buildup is best handled by adding specialized cleaner to the fuel or taking it to a professional shop for ultrasonic cleaning. In short, washing a catalytic converter with water is pure nonsense—at best a waste of money, at worst a danger to driving safety. It’s just asking for trouble.
