What is the fault when the catalytic efficiency of the car catalyst is low?

[OCamille]

Low catalytic efficiency of the car catalyst may be caused by the use of leaded gasoline or a malfunctioning oxygen sensor in the car leading to excessively low efficiency. Below is an introduction to the related content of the three-way catalytic converter: Three-way catalytic converter: The three-way catalytic converter is the most important external purification device installed in the car's exhaust system. It converts harmful gases such as CO, HC, and NOx emitted from the car's exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. Purifying agent: When high-temperature car exhaust passes through the purification device, the purifying agent in the three-way catalytic converter enhances the activity of the three gases CO, HC, and NOx, promoting certain oxidation-reduction chemical reactions. Among them, CO oxidizes at high temperatures into colorless, non-toxic carbon dioxide gas; HC compounds oxidize at high temperatures into water (H2O) and carbon dioxide; NOx is reduced into nitrogen and oxygen. The three harmful gases are transformed into harmless gases, thereby purifying the car's exhaust.