When a technician notices an OEM catalytic converter missing and a small aftermarket one present, what action should be taken?

When a technician encounters a situation where the original equipment manufacturer (OEM) catalytic converter is missing and has been replaced by a small aftermarket one, the appropriate action is to find the Executive Order Number (EO#) for the aftermarket catalytic converter.

This is important because the EO# indicates that the aftermarket part has been tested and certified by the California Air Resources Board (CARB) or another regulatory agency for emissions compliance. If the aftermarket catalytic converter is authorized for use in the specific vehicle, it may be legal and acceptable for the smog check. Conversely, without verifying the EO#, it cannot be determined if the replacement part meets the necessary emissions standards, which is crucial for passing the inspection.

While replacing the aftermarket converter with an OEM part might ensure compliance, it may not be necessary if the aftermarket converter is valid. Ignoring it or failing the vehicle outright without investigation would not provide a thorough and fair assessment of the vehicle's emissions system. Therefore, confirming the legitimacy and compliance of the aftermarket part through its EO# is the most responsible and appropriate action to take in this scenario.