How can technicians determine if an exhaust system is restricted?

Using a vacuum gauge connected to the intake is a reliable method for technicians to determine if an exhaust system is restricted. When the exhaust system is functioning properly, the vacuum gauge will show a normal reading. However, if the exhaust is restricted, the gauge will indicate a higher-than-normal vacuum reading since the engine is struggling to expel exhaust gases effectively. This method allows for a quantitative assessment of the exhaust flow and can help pinpoint restrictions that may not be visible or easily detectable through other means.

In contrast, while examining the exhaust tips visually can reveal some issues such as rust or soot buildup, it may not provide a comprehensive understanding of the entire exhaust system's health. Checking for engine overheating can indicate a problem, but it is not specific to exhaust restrictions and can be caused by various other issues unrelated to the exhaust system. Measuring the temperature of the exhaust gases may provide some information, but it is more useful in diagnosing combustion efficiency or catalyst performance rather than directly identifying restrictions in the exhaust flow. Therefore, using a vacuum gauge is a more accurate and direct method for assessing exhaust system restrictions.