What does the fault code indicating catalytic converter aging mean?
2 Answers
The faults of the catalytic converter generally include clogging, cracking, overheating damage, and the fault code "low catalytic converter efficiency," commonly referred to as catalytic converter aging. The low conversion efficiency of the catalytic converter is mainly due to the catalyst being covered by heavy metals and impurities in the exhaust, which primarily come from poor-quality fuel and engine oil participating in combustion, such as leaded gasoline or engine oil additives containing heavy metals. Here is more information about the catalytic converter: 1. The catalytic converter refers to the device that converts harmful gases like CO, HC, and NOx in vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. It mainly uses a catalytic converter, whose core component is a porous ceramic material installed in a specially designed exhaust pipe. It is called a "carrier" because it does not participate in the catalytic reaction itself but is coated with precious metals like platinum, rhodium, palladium, and rare earth coatings. It is the most important external purification device installed in the vehicle's exhaust system. 2. The working principle of the catalytic converter is: when high-temperature vehicle exhaust passes through the purification device, the catalyst in the catalytic converter enhances the activity of CO, hydrocarbons, and NOx, promoting certain oxidation-reduction chemical reactions. Among them, CO oxidizes at high temperatures to form colorless, non-toxic carbon dioxide gas; hydrocarbons oxidize at high temperatures to form water (H2O) and carbon dioxide; and NOx is reduced to nitrogen and oxygen. These three harmful gases are transformed into harmless gases, thereby purifying the vehicle exhaust. The prerequisite is that there is still oxygen available, and the air-fuel ratio must be reasonable.
When the catalytic converter fault code appeared on my dashboard, I immediately realized it indicated the exhaust system's catalytic converter had aged and failed. The catalytic converter is responsible for transforming harmful engine emissions into harmless substances, such as reducing pollutants in the exhaust. The primary causes of aging are typically high annual mileage, engine oil leaking into the exhaust system, or the use of low-quality fuel leading to internal carbon buildup and blockage. Driving this old car with this issue, I noticed significantly slower acceleration, a sharp increase in fuel consumption, and potential failure in the annual emissions test. I recommend first using an OBD diagnostic tool to confirm the fault code is P0420, then checking if the oxygen sensors are functioning properly. If the catalytic converter is indeed faulty, the only solution is replacement, though it can be costly. Some cleaning services might offer temporary relief. To prevent such issues, I make sure to maintain the engine properly—like regularly changing the air filter and using high-quality gasoline—since replacing a catalytic converter costs thousands, which is quite painful.
