Can an EIS machine be used to assess emissions in a vehicle with a faulty vacuum pump?

Using an EIS (Emissions Inspection System) machine on a vehicle with a faulty vacuum pump will likely lead to inaccurate results. The vacuum pump is integral to ensuring that various systems within the vehicle, such as the fuel metering and air-fuel mixture, are functioning properly. A faulty vacuum pump can cause incorrect readings, as the emissions measurement relies on accurate pressure and flow data to assess exhaust emissions. Therefore, any existing faults in the vehicle's systems, particularly those related to the vacuum, will compromise the reliability of the emissions data obtained from the EIS machine. This is crucial because an accurate assessment is necessary for compliance and ensuring that the vehicle meets environmental standards.