Emissions testing is a process used to measure the amount of pollutants released by a vehicle's engine. This testing helps ensure that cars and trucks meet environmental standards set by government regulations. By checking emissions, authorities can identify vehicles that may be contributing to air pollution and require repairs or upgrades. The tests typically involve analyzing exhaust gases while the vehicle is running. If a vehicle fails the emissions test, it may need repairs to its engine, catalytic converter, or exhaust system to reduce harmful emissions. Regular testing helps protect the environment and public health by promoting cleaner air.