What Causes Vehicle Exhaust Emissions to Fail Inspection?

[ElianaLee]

Vehicle exhaust emissions may fail inspection due to the following reasons: 1. High sulfur and phosphorus content in gasoline, which forms chemical complexes on the surface of the oxygen sensor and catalytic converter; 2. Congested urban traffic with frequent stops, starts, and idling, leading to incomplete combustion products adhering to the catalytic converter surface; 3. Engine carbon deposits and particulate matter clogging the catalytic converter. Solutions for failing emissions tests include: 1. Driving in 4th gear for several dozen kilometers; 2. Maintaining engine warmth by keeping it idling; 3. Cleaning the catalytic converter. As one of the primary sources of air pollution, vehicle exhaust contains substantial amounts of harmful substances, including carbon monoxide, nitrogen oxides, hydrocarbons, and solid suspended particles. Sulfur dioxide in exhaust has a strong irritating odor and, when reaching certain concentrations, can easily lead to acid rain, causing soil and water source acidification that affects crop and forest growth.