What are the tips for excessive CO in exhaust emission testing?
3 Answers
Excessive CO in exhaust emission testing should prompt checks on the air filter, spark plugs, intake air temperature sensor, intake pipe pressure sensor, and the addition of dual-core friction-reducing repair agents and high-efficiency cleaners. If ineffective, clean the three-way catalytic converter. Below is relevant information: 1. Excessive exhaust emissions mainly refer to carbon monoxide, nitrogen oxides, nitrogen-hydrogen compounds, etc., exceeding national exhaust emission standards. These excessive emissions are directly related to carbon deposits inside the fuel supply system. More carbon deposits result in more severe excessive emissions, while fewer deposits lead to milder cases. 2. Excessive carbon monoxide in car exhaust is primarily due to poor combustion. The main causes of this phenomenon include: failed spark plugs, poor ignition, excessive cylinder wall clearance, uncalibrated valve timing, failed three-way catalytic converter, poor fuel injector atomization, etc.
My old classic car always failed the emissions test with excessive CO levels. Later, I discovered the trick is actually proper car maintenance. Don't always look for shortcuts—check the spark plugs and ignition system. When they wear out, they cause incomplete combustion, leading to high carbon monoxide emissions. Replacing the air filter is also crucial; it ensures sufficient air intake for cleaner gasoline combustion. The oxygen sensor is another key component—if it's faulty, it messes up the air-fuel mixture. I replaced one once, and the car passed the test immediately. Before the test, warm up the car for half an hour and drive a few kilometers on the highway to heat up the engine. A hotter exhaust pipe makes it easier to meet the standards. Regular oil changes and using high-quality fuel also reduce carbon buildup. These simple maintenance steps significantly improve emissions and even save fuel.
When I first bought my car, it failed the emissions test due to excessive CO levels. I was so anxious that I researched extensively to figure out what to do. The trick is to prepare in advance: accelerate a few times on the way to the testing station to clear carbon deposits and ensure the engine burns fuel at its optimal state. Make sure the catalytic converter is functioning properly—if it's clogged, CO levels will be high. I cleaned my catalytic converter once, and it worked well. Don’t forget to check if the fuel tank cap is leaking or if the fuel pump pressure is normal, as these details can affect the air-fuel mixture ratio. Use higher-grade gasoline during daily driving to reduce impurities, and avoid cold starts before the test. After trying these methods, my car passed the next test—saving money and ensuring safety without resorting to shady fixes.
