Under what conditions do cars emit more carbon monoxide?
2 Answers
Cars emit more carbon monoxide when idling with the engine running. Solutions for non-compliant vehicle emissions include: 1. Replacing spark plugs; 2. Adjusting ignition timing; 3. Cleaning the throttle valve with cleaner; 4. Switching to 97-octane gasoline or 97-octane ethanol gasoline; 5. Using vehicle exhaust purifiers; 6. Cleaning distributor contacts and rotor contacts; 7. Cleaning the air filter; 8. Cleaning the three-way catalytic converter and oxygen sensor. Methods to check a vehicle's emission standard: 1. Check the vehicle conformity certificate: The emission standard is clearly stated in the certificate; 2. Look for the vehicle inventory list: The emission standard can be found in the vehicle information section; 3. Check the conformity certificate: It indicates the corresponding emission standard; 4. Inspect the vehicle's environmental protection label: The back of the environmental protection label on the front windshield clearly marks the vehicle's emission standard.
I once tested the exhaust emissions of an old car with an instrument, and the situations where carbon monoxide levels were off the charts were basically these: It's most severe during cold starts, especially in winter when the engine isn't fully warmed up. The fuel injection is rich, and gasoline doesn't burn completely, resulting in thick black smoke. It's even scarier during traffic jams—half an hour of stop-and-go traffic produces five times more emissions than cruising on the highway. Older cars require extra attention. For example, our company's decade-old van, idling in a tunnel with the AC on, later tested at carbon monoxide levels twenty times over the limit. Also, if you smell gasoline accompanied by popping sounds from the exhaust pipe, it's likely poor combustion—get the oxygen sensor and spark plugs checked ASAP. My advice: Don't warm up the car for more than two minutes, close the windows and switch to recirculation mode in traffic, and clean the throttle body regularly.
