Can the Three-Way Catalytic Converter Be Washed with Water?

[AmyRose]

Yes, the three-way catalytic converter can be washed with water. The cleaning method is as follows: 1. Start the engine and turn it off after the water temperature normalizes; 2. Pour the cleaning solution into a specialized device, and connect the device's output connector to the vacuum tube; 3. Start the engine, maintain the RPM at around 2000 rpm, open the flow control valve, and slowly drip the cleaning solution into the intake manifold; 4. After cleaning, keep the engine running for 3 to 5 minutes. The three-way catalytic converter is an external purification device installed in the vehicle's exhaust system. It converts harmful carbon monoxide, hydrocarbons, and nitrogen oxides from vehicle emissions into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions.

[Corinne]

Last time a buddy insisted on using a high-pressure water gun to clean the catalytic converter and ended up ruining it completely. In over a decade of repairing cars, I've seen too many cases like this—this part really shouldn't get wet. Inside the catalytic converter is a delicate ceramic honeycomb structure coated with precious metal catalysts like platinum, rhodium, and palladium. Water pressure can crack the ceramic and strip off the coating. Common issues after washing include exhaust blockage, excessive emissions, engine warning lights, and in severe cases, the entire converter being scrapped. If there's a carbon buildup problem, it's best to use a dedicated catalytic converter cleaner or have it professionally removed and soaked in chemical solution. Keeping the engine combustion in good condition is far more important. Remember, replacing this thing costs thousands—don't mess with your wallet.

[StPiper]

My old car used to have strong exhaust fumes, and my elderly neighbor said just washing it with water would do the trick. I actually believed him and spent half a day spraying the exhaust pipe with a hose. The next day, the car had weak acceleration and made a sputtering sound. When the mechanic opened it up, the ceramic substrate inside the catalytic converter was completely shattered. Turns out, the catalytic converter can crack when suddenly cooled after high-temperature operation, and water can wash carbon deposits into the honeycomb channels, causing blockages. Now, every time I wash the car, I make sure the apprentices don’t touch the exhaust pipe area—it’s very delicate and wasn’t designed to be waterproof. The repair cost me over 2,000 yuan—a painful lesson. Don’t make the same mistake of trying to save effort by washing it with water.

[ONaomi]

The interior of the three-way catalytic converter features a honeycomb ceramic structure coated with precious metal catalysts. The risks of water washing mainly lie in two aspects: First, thermal expansion and contraction—the converter can reach several hundred degrees Celsius right after stopping the vehicle, and sudden exposure to cold water can easily cause cracks. Second, water flow can damage the catalytic coating and cause carbon deposits to harden, blocking the channels. The direct consequences are reduced catalytic efficiency, excessive exhaust emissions, and degraded vehicle performance. The correct cleaning methods involve using specialized chemical cleaners or regularly driving at high speeds to allow the exhaust heat to automatically remove carbon deposits. After all, replacing a catalytic converter is quite expensive, so caution is warranted.