What is the primary function of the exhaust probe during emissions testing?

The primary function of the exhaust probe during emissions testing is to analyze gas composition. This tool is vital for determining the levels of various pollutants emitted from the vehicle's exhaust system, such as carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter. By analyzing the gas composition, technicians can assess whether a vehicle meets the required emissions standards and identify any potential issues related to emissions control systems. This information is crucial in understanding the environmental impact of the vehicle and ensuring compliance with regulations.

In contrast, measuring air pressure, checking fuel levels, or monitoring engine temperature are important aspects of vehicle diagnostics and performance testing but do not directly relate to the purpose of the exhaust probe in assessing emissions.