The three-way catalyst converter uses rhodium and other catalytic converters to limit the content of pollutants such as HC, Co and NOx in the exhaust gas.
And other catalytic converters to limit the content of pollutants such as HC, Co and NOx in exhaust gas.
The TWC is located on the exhaust duct, between the exhaust manifold and the muffler. Its role is to convert harmful substances (CO, NOX, HC) in the exhaust into harmless substances.
After the TWC, the second-generation diagnostic system uses an oxygen sensor combined with the oxygen sensor before the TWC to monitor the quality of the TWC. If the TWC conversion efficiency is low, the engine fault light is turned on. At the same time, some vehicles enable the standby mode, which can drive, but the performance is not good.
Relationship between the two The relationship between the conversion efficiency of TWC and the air-fuel ratio, the three-way catalyst converter requires that the air-fuel ratio be accurately controlled within the optimal range near the theoretical value, otherwise the three harmful emissions cannot be converted at a high efficiency at the same time. 1. If a richer mixture is entered in the cylinder, O2 is insufficient, and the engine burns more CO and HC, and the ternary catalyst converter has limited oxygen storage capacity, which cannot fully oxidize CO and HC, and TWC conversion efficiency Low, because the O2 concentration is low, so the amount of NOX generated is small, and the TWC conversion efficiency is high. 2. If the mixture entering the cylinder is a lean mixture, under this oxygen-enriched condition, the combustion produces more NOX, less CO and HC; because the reducing ability of the three-way catalyst converter is also limited, so NOx in the exhaust gas The content is higher.