Which condition would result in a vehicle being rejected for exhaust system issues?

A vehicle would be rejected for exhaust system issues if the exhaust pipe has a leak at a seam. This is because an exhaust leak can pose serious environmental and safety concerns. Leaks in the exhaust system can lead to the release of harmful gases, such as carbon monoxide, into the atmosphere, which is not only detrimental to air quality but can also jeopardize the health of the vehicle's occupants. A seam leak indicates a failure in the exhaust system’s integrity and could result in excessive noise, poor engine performance, and increased emissions, all of which are grounds for rejection during an inspection.

In contrast, a muffler with a minor dent, a rusted but intact tailpipe, and a securely attached manifold gasket would typically not result in immediate rejection. A minor dent may not significantly affect the functionality of the muffler, a rusted tailpipe that remains intact might still operate effectively without leaking harmful gases, and a properly secured manifold gasket indicates a stable connection without immediate concerns. Thus, the presence of a leak at a seam in the exhaust pipe is the most serious issue that warrants rejection.