What to Do If Vehicle Fails Emission Test?

[IsabelaLynn]

Methods to address vehicle emission test failures include cleaning the three-way catalytic converter, cleaning the front oxygen sensor, switching to higher-quality gasoline, and checking engine operating conditions. Below are specific solutions for emission test failures: 1. Clean the three-way catalytic converter: As the key component for exhaust purification, consider using oxalic acid solution. Remove the three-way catalytic converter, fill it with oxalic acid solution, and let it sit for half an hour. 2. Clean the front oxygen sensor: Carbon deposits from incomplete engine combustion can accumulate on the oxygen sensor's surface, leading to sensor failure over time. It can be cleaned along with the three-way catalytic converter. 3. Switch to higher-quality gasoline: High-quality gasoline promotes complete combustion and may slightly improve exhaust emissions. If necessary, after switching, consider driving at highway speeds before retesting. 4. Check engine operating conditions: Poor engine conditions inevitably affect exhaust emissions. Incomplete combustion of the air-fuel mixture will result in poor emissions, and excessive carbon buildup can also impact engine performance.