Troubleshooting of automobile: low efficiency of catalyst. How to judge whether the spark plug, oxygen sensor, battery and catalyst need to be replaced?

OBD's P0430 fault code is applicable to all models;

This fault code indicates that the electronic control unit (ECU) has detected that the efficiency of the catalytic converter system is lower than the minimum acceptable value. The failure causes include tail gas leakage near the exhaust pipe or exhaust manifold, catalyst box failure, engine coolant temperature (ECT) sensor failure, engine fire or timing lag, dirty engine oil, oxygen sensor failure, high fuel system pressure, etc.

Focus on oxygen sensors and catalysts (three-way catalysis). The oxygen sensor can read the data by computer to judge whether it is good or not. Pay attention to heating above 600 degrees Celsius to read accurate data. The catalyst is integrated in the three-way catalytic converter, which is difficult to detect. It can be cleaned and repaired in China, but I don't know in America.

I hope it helps you.