What type of repair may be conducted during an emissions test?

Gas cap replacement is a type of repair that specifically addresses one of the common issues that can cause a vehicle to fail an emissions test. The gas cap plays a crucial role in maintaining the integrity of the fuel system and preventing fuel vapors from escaping into the atmosphere. If the gas cap is damaged, improperly sealed, or missing, it can lead to increased emissions. During an emissions test, if the technician finds that the gas cap is not functioning properly, replacing it may be required in order to help the vehicle pass the test.

In contrast, while brake inspections, oil changes, and tire rotations are important maintenance tasks, they do not directly relate to emissions control. These services focus on the vehicle's safety and operational performance rather than addressing emissions-related components. Therefore, they would not be conducted as part of an emissions test or considered necessary repairs in that context.