What is the purpose of a car's three-way catalytic converter?

[DelaneyFitz]

The function of a three-way catalytic converter is to transform harmful gases emitted by a car into harmless gases. Below is relevant information about the three-way catalytic converter: 1. Working principle: When high-temperature exhaust gases pass through the purification device, the purifying agent in the three-way catalytic converter enhances the activity of three gases—CO, HC, and NOx—promoting certain oxidation-reduction chemical reactions. Among these, CO oxidizes at high temperatures into colorless, non-toxic carbon dioxide gas; HC compounds oxidize into water (H2O) and carbon dioxide; and NOx is reduced into nitrogen and oxygen. 2. Consequences of damage: If the three-way catalytic converter is damaged, the secondary oxygen sensor on it will fail to provide accurate data to the car's computer, leading to either excessively lean or rich fuel mixture concentration. A lean mixture can cause ignition difficulties, lack of power while driving, engine backfiring, etc., while a rich mixture can increase fuel consumption, result in incomplete combustion, and cause severe carbon buildup in cylinders and spark plugs. When such faults occur, the engine warning light should illuminate.