Under What Conditions Do Cars Emit More Carbon Monoxide?
2 Answers
Cars emit more carbon monoxide when idling with the engine running. The car engine's combustion chamber tends to produce carbon monoxide when operating at high temperatures. When the engine is left running while parked and waiting, there is no load, and the fuel burns without performing work, leading to higher combustion chamber temperatures and increased carbon monoxide production. The reasons for excessive carbon monoxide emissions include: 1. Overly lean air-fuel mixture: insufficient cylinder pressure, low engine temperature, leakage from the combustion chamber to the crankshaft, fuel line leaks, or a damaged fuel pressure regulator; 2. Overly rich air-fuel mixture: gasoline burns in an oxygen-deficient environment, producing carbon monoxide. In cases of a rich mixture, first check the choke valve opening and adjust the fuel needle; 3. Inaccurate ignition timing, intermittent misfiring, faulty temperature sensors, leaking or clogged fuel injectors, excessively high or low fuel pressure, and other factors leading to high HC readings; 4. Uneven fuel injector atomization, resulting in an air-fuel ratio that fails to meet standards and incomplete combustion.
As an ordinary person who drives frequently, I've noticed that cars emit particularly high levels of carbon monoxide when idling or in neutral gear—such as during traffic jams when the engine is running but the car isn't moving, or when warming up the engine for too long. Cold starts also result in higher emissions, as the engine's low temperature leads to incomplete fuel combustion. These conditions are especially common in urban traffic, where prolonged idling not only wastes fuel but also increases CO concentration inside the car, posing health risks. I recommend avoiding prolonged engine idling—for example, turning off the engine if stopped at a light for more than a minute. During routine maintenance, check the oxygen sensor and fuel system to ensure proper air-fuel mixture and reduce emissions. Additionally, problems are more likely to occur in high-altitude areas or places with insufficient oxygen, so drivers should pay attention to ventilation. In short, reducing idle habits protects the environment and is more economical.
