Where is the three-way catalytic converter located on a car?
2 Answers
The three-way catalytic converter is located on the exhaust manifold, which is the header section of the exhaust pipe. The three-way catalytic converter is the most important external purification device installed in the vehicle's exhaust system. It converts harmful gases such as CO, HC, and NOx emitted from vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. When high-temperature vehicle exhaust passes through the purification device, the catalyst in the three-way catalytic converter enhances the activity of CO, HC, and NOx gases, promoting specific oxidation-reduction chemical reactions. CO oxidizes at high temperatures into colorless, non-toxic carbon dioxide gas; HC compounds oxidize into water (H2O) and carbon dioxide; and NOx reduces into nitrogen and oxygen. These three harmful gases are transformed into harmless gases, thereby purifying the vehicle exhaust.
I often deal with the catalytic converter when repairing cars. It is generally installed at the front end of the vehicle's exhaust system, right after the engine's exhaust manifold. Simply put, it's located under the car's chassis, near the center-front area of the vehicle, usually between the wheels. The reason for this placement is that the catalytic converter requires high temperatures to function effectively. The exhaust gases just expelled from the engine are at their hottest, enabling the catalytic reaction to start quickly and purify harmful emissions. If you look under the chassis, it appears as a metal canister or a bulging component fixed to the exhaust pipe. Be cautious not to burn yourself during installation, as the temperature is very high after the engine has been running. Improper positioning may lead to excessive emissions, triggering the malfunction indicator light and affecting the vehicle's annual inspection pass rate. It's recommended to regularly inspect the exhaust system and keep it clean to prolong its service life.
