Technician A says that the best way to diagnose an EVAP system leak is to use a smoke machine to introduce vapor into the system and visually inspect for leaks. Technician B says that a loose or faulty gas cap can trigger an EVAP system leak code and should be checked first before performing more advanced diagnostics. Who is correct? Technician A Technician B Both A and B Neither A nor B

Both Technician A and Technician B are correct.<br /><br />Technician A is correct in stating that using a smoke machine to introduce vapor into the EVAP system and visually inspecting for leaks is an effective method to diagnose an EVAP system leak. This method allows for the identification of visible leaks in the EVAP system.<br /><br />Technician B is also correct in stating that a loose or faulty gas cap can trigger an EVAP system leak code and should be checked first before performing more advanced diagnostics. A loose or faulty gas cap can cause the EVAP system to malfunction and trigger a leak code, so it is important to check the gas cap as part of the diagnostic process.<br /><br />Therefore, both Technician A and Technician B are correct in their statements.