What types of repairs might a vehicle owner be required to complete after a failing emissions inspection?

After a vehicle fails an emissions inspection, the focus is primarily on repairs that directly impact the emissions produced by the vehicle. Replacing components such as catalytic converters and oxygen sensors is crucial because these parts are integral to the vehicle's emission control system.

Catalytic converters play a vital role in converting harmful gases like carbon monoxide and hydrocarbons from the engine's exhaust into less harmful emissions before they are released into the atmosphere. If this component is malfunctioning or damaged, it can lead to increased emissions, which is why it might need replacement following a failed inspection.

Oxygen sensors, on the other hand, monitor the level of oxygen in the exhaust and send this information to the engine control unit. This data helps the engine run efficiently and reduces emissions by ensuring the correct fuel-to-air mixture. A faulty oxygen sensor can lead to improper fuel mixtures and higher emissions.

In summary, repairing or replacing these emission-related components is often legally required to ensure that vehicles meet environmental regulations and operate effectively, which makes this choice the correct answer.