What to Do If a Vehicle Fails the Exhaust Emission Test?
2 Answers
Solutions for a vehicle failing the exhaust emission test include: 1. Cleaning the three-way catalytic converter and oxygen sensor; 2. Cleaning or replacing the spark plugs; 3. Performing a deep cleaning of the engine interior. Reasons for failing the exhaust emission test are: 1. Frequent urban driving leading to excessive engine carbon buildup; 2. Using low-quality gasoline; 3. Wear and tear of engine components. Vehicle exhaust refers to the waste gases produced during vehicle operation, containing various compounds, including pollutants such as particulate matter, carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides, lead, and sulfur oxides.
If my car fails the tailpipe emissions test, it's most likely due to an issue with the emission system. I think the three most common causes are: the catalytic converter might be clogged or malfunctioning—this part is responsible for purifying exhaust gases; if the oxygen sensor is aged or damaged, an incorrect air-fuel mixture ratio can lead to excessive emissions; or it could be that the fuel injectors have too much carbon buildup, causing incomplete combustion. I suggest doing a simple self-check first, like seeing if the air filter is dirty and needs replacement, or checking if any trouble codes indicate sensor problems. If all these seem normal and the issue persists, then you'll need to find a reliable repair shop for professional equipment diagnostics. After all, failing emissions not only affects the car's condition but might also result in traffic police fines, so don’t delay—get it fixed promptly. Replacing a small part might cost just a hundred or so bucks, which is much better than waiting for a bigger problem. I usually let the engine idle for a few minutes before driving to warm it up, as this helps reduce carbon buildup.
