What is a reason for failing an exhaust system inspection?

Failing an exhaust system inspection can occur due to damage and corrosion because these conditions can significantly impair the exhaust system's performance and safety. Damage might include perforations, cracks, or severe dents that can lead to exhaust leaks, which can allow harmful gases, like carbon monoxide, to enter the vehicle’s cabin. Corrosion, on the other hand, indicates the material has deteriorated, often due to prolonged exposure to moisture and road salt. This decay can weaken the structural integrity of the exhaust components, making them less effective at directing exhaust gases away from the engine and passenger area.

While the presence of rust may signal a potential problem, it does not always indicate a failure on its own; light rust that has not compromised the material may not cause an inspection failure. A resonator is typically part of the exhaust system designed to reduce noise and does not affect the system's legality or safety directly. Similarly, even though a missing muffler is a concern, it may not be the sole reason for failure in every case unless it is clearly shown to compromise exhaust effectiveness or legality, as some vehicles may operate without one under specific conditions. However, damage and corrosion are definitive indicators of failure due to the threats they pose to both vehicle function and occupant safety.