What are the reasons and solutions for unqualified vehicle exhaust emissions?
2 Answers
Reasons and solutions for unqualified vehicle exhaust emissions are as follows: 1. Oxygen sensor failure: There are generally two oxygen sensors, one located behind the exhaust manifold and the other behind the three-way catalytic converter. The oxygen sensor is responsible for detecting the oxygen content in the exhaust. It sends signals to the ECU, which then adjusts the air-fuel ratio based on these signals. If the oxygen sensor is damaged, the ECU cannot accurately adjust the air-fuel ratio, leading to either a too rich or too lean mixture, resulting in unqualified exhaust emissions. Solution: Replace the oxygen sensor. 2. Three-way catalytic converter failure. Solution: Replace the three-way catalytic converter. 3. Poor gasoline atomization. Solution: Replace the gasoline in time. 4. Oxygen sensor malfunction. Solution: The vehicle's oxygen sensor needs to be replaced.
I've been driving for over twenty years and have encountered the issue of failing emissions tests several times. The main reason is usually a faulty catalytic converter, which is responsible for purifying exhaust gases. When it ages, gets clogged, or cracks, it stops functioning properly. Another common issue is a malfunctioning oxygen sensor. The sensor is installed on the exhaust pipe to monitor oxygen levels and help the computer adjust the air-fuel mixture. If it fails, incomplete combustion occurs, leading to thicker exhaust emissions. A dirty air filter can also cause problems by restricting airflow. The solution is straightforward: first, use a diagnostic tool to read the fault codes and confirm the cause. If the catalytic converter is damaged, it must be replaced—it’s an expense, but necessary. Oxygen sensor issues are simpler to fix—just replace it. Prevention is key. I recommend checking the exhaust system every six months, cleaning the air filter during oil changes, and using higher-grade fuel to reduce carbon buildup. Older vehicles are particularly prone to these issues, so timely maintenance can save both hassle and money.
