What to Do If the Vehicle Fails the Environmental Inspection?

[MacLawson]

It might be an issue with the catalytic converter. Here are some relevant details about the catalytic converter: 1. Principle of the Catalytic Converter: Vehicle exhaust contains many pollutants, with the most significant being carbon monoxide, hydrocarbons, and nitrogen oxides. Normally, after oxidation and reduction processes, the catalytic converter converts these into harmless carbon dioxide, nitrogen, and water, achieving purification. The catalytic converter is called a "three-way" converter because it contains three precious metals: platinum (Pt), rhodium (Rh), and palladium (Pd), hence the name "three-way." 2. Solution: Before the inspection, drive on the highway for a while to bring the catalytic converter up to its operating temperature before testing. The most important point is not to turn off the engine before the inspection to keep the catalytic converter at a certain temperature. If it still fails, directly clean the catalytic converter and then retest to see if it passes.

[DiOlivia]

My car failed the emission test three times last year, and I've summarized some tips. First, check the mileage - vehicles over 80,000 km have an 80% chance of needing catalytic converter replacement. Always choose OEM parts when replacing, as aftermarket parts may cause recurring issues. Secondly, inspect the EVAP system - a clogged charcoal canister will cause HC emissions to exceed limits. Use quality synthetic engine oil during maintenance to reduce particulate emissions. Schedule retests on sunny days when humidity is low for more accurate readings. Finally, avoid prolonged idling at the test station entrance as engine overheating will spike NOx levels. Paying attention to these details should get you through the test.