How to Solve Low Efficiency of Three-Way Catalytic Converter?
3 Answers
The only solution for low efficiency of a three-way catalytic converter is replacement. If the efficiency is too low and left unrepaired, it may cause the three-way catalytic converter to malfunction and result in excessive exhaust emissions. A clogged three-way catalytic converter not only significantly increases vehicle fuel consumption, reduces power, and leads to excessive exhaust emissions but, more seriously, can cause the exhaust pipe to overheat and turn red, potentially leading to vehicle self-ignition. How to determine the condition of a three-way catalytic converter: Visual inspection. Check the exterior of the three-way catalytic converter for any damage or discoloration. If there are scratches, cracks, etc., it is likely that the converter has been damaged. If there are noticeable gray spots in the center of the converter's protective cover, severe discoloration spots, or purple marks on the shell, it may indicate overheating issues. Observe engine exhaust conditions. Place your hand near the exhaust pipe outlet to feel the exhaust flow and check if the three-way catalytic converter is clogged or if there is poor exhaust flow. Another method is to open the air filter, remove the filter element, and observe if there is exhaust backflow during rapid acceleration, which indicates poor engine exhaust. To test the condition of the TWC (Three-Way Catalytic Converter), check if the secondary air injection pump is functioning properly. Use an infrared thermometer to assess. Compare the temperature difference between the front and rear of the TWC using an infrared thermometer. If the temperature difference between the inlet and outlet of the three-way catalytic converter is less than 10°C, the TWC is likely damaged.
The most common reasons for reduced catalytic converter efficiency are oxygen sensor issues or converter clogging. Don't rush to replace parts - first use an OBD scanner to check for relevant trouble codes. If it's an oxygen sensor problem, replacing it can significantly improve efficiency. For internal carbon buildup or contamination in the converter, try adding catalytic converter cleaner and taking a long drive to burn off deposits at high temperatures. Avoid frequent short trips with repeated starts/stops in daily driving, and use high-quality low-sulfur fuel to minimize carbon buildup. If problems persist, have a professional shop check exhaust temperatures with an infrared thermometer to diagnose converter function. While converter replacement is expensive (costing several thousand yuan), it solves emission compliance issues and ensures smooth annual inspection passage.
Low catalytic converter efficiency? I'd first check the engine condition since abnormal air-fuel mixture is the primary cause. Examine whether the oxygen sensor data stream fluctuates, if the ignition coils and spark plugs are aged, or if the air filter is dirty. These issues can all lead to excessively low exhaust temperatures affecting the converter. Money-saving solutions: Replace with an aftermarket oxygen sensor for 200-300 RMB, or try a bottle of catalytic converter cleaner for a few dozen RMB. Alternatively, opt for a used converter from a salvage yard at half the price of a new one, but be cautious as used parts may have unknown issues. Regular engine maintenance is crucial—inspect the ignition system every 20,000 km, use 95-octane fuel to reduce carbon buildup, and efficiency will last longer. For city driving, occasional highway trips help fully heat the converter, effectively preventing problems.
