Why does the catalytic converter warning light keep coming on in the 8th-generation Accord?
2 Answers
Fault light indicates a blocked catalytic converter. There are many reasons for the blockage, such as: 1. Poor fuel injector atomization. 2. Incomplete engine combustion. 3. Oxygen sensor failure. 4. Temporary poisoning of the catalytic converter or catalytic converter failure. Additional information: How a catalytic converter works: When high-temperature vehicle exhaust passes through the purification device, the purifying agent in the catalytic converter enhances the activity of CO, HC, and NOx gases, promoting certain oxidation-reduction reactions. Among them, CO oxidizes at high temperatures to form colorless, non-toxic carbon dioxide gas; HC compounds oxidize at high temperatures into water and carbon dioxide; NOx is reduced to nitrogen and oxygen. The three harmful gases are transformed into harmless gases, thereby purifying the vehicle exhaust.
My own eighth-generation Accord also frequently has the catalytic converter warning light come on, which is quite annoying. The most common issue is with the oxygen sensor, which is responsible for monitoring exhaust emissions. If it gets dirty or fails, it can trigger false error reports. Additionally, the catalytic converter itself might be clogged or cracked, especially after years of driving, as carbon buildup becomes severe. Excessive exhaust emissions from the engine can also trigger this light. I recommend first finding a place to scan the trouble codes with a diagnostic tool to identify the specific code before rushing to replace parts, as sometimes it's just caused by poor fuel quality or minor issues. For regular maintenance, using a high-quality fuel additive for cleaning a few times might help alleviate the problem. If the light remains on, don’t delay too long—get it checked at a specialized repair shop to avoid engine performance degradation or failing the annual inspection. Anyway, this issue is quite common and not too troublesome to handle, but it does require some effort to pinpoint the root cause.
