Which of the following would not be a cause for rejection during an exhaust inspection?

During an exhaust inspection, one of the key criteria is the integrity and functionality of the exhaust system. A system held in place with metal wire is not considered a proper method of securing exhaust components, as this does not provide the necessary stability and may lead to additional issues, such as leaks or detachment.

In contrast, a joint that is loose or leaking, the absence of a muffler, and patched holes in the exhaust system all present serious concerns. Loose or leaking joints can contribute to harmful emissions and noise pollution, while a muffler is essential for reducing noise generated by the engine. Patching holes can sometimes be a temporary solution but does not meet standards for long-term safety and effectiveness if not done properly.

Therefore, the condition of using metal wire to hold a component in place fails to conform to acceptable standards, making it the correct response to identify as a cause for rejection during an exhaust inspection.