What to Do If a Vehicle Fails the Exhaust Emission Test?
2 Answers
Here are several reasons why a vehicle might fail the exhaust emission test and the corresponding solutions: 1. Dirty throttle body, intake manifold, or fuel injectors: Clean the throttle body, intake manifold, and fuel injectors. Generally, cleaning the throttle body, intake manifold, and fuel injectors is recommended every 30,000 to 40,000 kilometers. If the vehicle is used in harsh conditions or is significantly aged, the cleaning interval can be appropriately shortened. 2. Engine oil burning: Conduct a thorough inspection of the engine. Identifying the root cause of oil burning not only resolves the oil burning issue but can also turn the exhaust from non-compliant to compliant. 3. Issues with the catalytic converter: When a vehicle fails the exhaust emission test, a common practice is to 'clean the catalytic converter.' Therefore, cleaning and inspecting the catalytic converter is the most common solution.
As an experienced car enthusiast who often tinkers with vehicles, I was really sweating when my car failed the emissions test during the inspection. After some thought, the reason might be that the air filter was too dirty and clogged the intake, leading to incomplete fuel combustion and a lot of black smoke. I simply replaced it with a new one for just 50 yuan, and the emissions passed the test on the next try. If this trick doesn't work, the problem is likely deeper, such as carbon buildup in the catalytic converter blocking the exhaust pipe, which requires professional cleaning or replacement at a shop. Remember, don't stubbornly drive a faulty car to the retest—it could lead to worse issues like engine cylinder scoring. Regular maintenance, like checking the filter every quarter, can prevent this. Also, saving a bit by using higher-quality fuel reduces carbon buildup, saving money and giving peace of mind.
