What Causes Excessive CO Emissions in Cars?
2 Answers
If a car is found to have excessive CO emissions during annual inspection, it is usually caused by a faulty oxygen sensor leading to excessive fuel injection, resulting in a large amount of incompletely burned CO. Here are the solutions: 1. Check the oxygen sensor. Professional repair: Have the manufacturer inspect and repair (replace the oxygen sensor or conduct a comprehensive check). Most engine electronic control systems have self-diagnostic functions. When the oxygen sensor or related components fail, the computer will automatically record the fault. Technicians only need to use a specialized decoder to read the fault code to identify the problem. 2. Self-check. If issues like unstable idling or poor acceleration are caused by the oxygen sensor, simply disconnect the oxygen sensor connector during inspection. If the engine fault disappears, it indicates the oxygen sensor is damaged and must be replaced. If the engine fault persists, further investigation is needed to identify other potential causes.
When I usually encounter excessive CO emissions during car repairs, the most common cause is an overly rich air-fuel mixture. If the fuel injectors are leaking or the air filter is clogged, the gasoline won't burn completely, resulting in black smoke, and the carbon monoxide levels will definitely exceed the standard. If the spark plugs fail to ignite, the cylinder temperature remains insufficient, leading to even more incomplete combustion. The catalytic converter is another issue – over time, it can get clogged with carbon deposits, significantly reducing its exhaust treatment capability. A faulty oxygen sensor is also troublesome as it regulates the air-fuel ratio; when it fails, the ECU starts delivering incorrect fuel amounts. These problems combined not only cause excessive emissions but also drastically increase fuel consumption. It's recommended to inspect the sensors and ignition system every 20,000 kilometers, and older vehicles should have their air filters replaced more frequently.
