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Smog Check
Also known as: Emissions Test, Pollution Test, Vehicle Emissions Inspection
A smog check, also called an emissions test, is a regulatory inspection required in many states to measure the pollutants emitted by a vehicle. The goal is to ensure cars meet minimum environmental standards and do not release excessive levels of harmful gases such as carbon monoxide, hydrocarbons, and nitrogen oxides. Smog checks are usually performed at certified inspection stations and may be required annually or biennially. Vehicles that fail a smog check must be repaired and retested before registration can be renewed. Common repairs include replacing oxygen sensors, catalytic converters, or addressing engine performance issues. Some exemptions exist for electric vehicles, hybrids, and newer models, depending on local regulations. Smog checks protect public health, reduce air pollution, and maintain compliance with federal clean air laws. For car owners, they represent both an environmental responsibility and a potential cost of maintenance.
Example
Maya owns a 10-year-old sedan that fails its smog check due to a faulty catalytic converter. She pays $1,200 for repairs and passes the retest, allowing her to renew her registration.