If an OEM air cleaner is missing and a non-approved aftermarket cleaner is installed, what should the technician do?

Choosing to research the Aftermarket Parts List (APL) is the most appropriate action when encountering a non-approved aftermarket air cleaner in a vehicle. Conducting research on the APL allows the technician to confirm whether the installed aftermarket air cleaner meets the necessary regulations and emissions standards. By doing this, the technician can ensure compliance with both regulatory requirements and the vehicle's performance needs, which is essential in smog checks.

This approach keeps the technician within the bounds of proper procedure, as it emphasizes the need for verification before taking any further action. The details from the APL can provide essential information about whether an aftermarket part is acceptable for use in vehicle emissions control systems.

In contrast, simply replacing the aftermarket cleaner with an OEM air cleaner does not account for the possibility of the aftermarket cleaner being compliant. Failing the vehicle without action could also lead to unnecessary penalties if the cleaner is acceptable, while ignoring the aftermarket cleaner altogether would neglect the responsibility to assess its compliance, ultimately compromising the integrity of the emissions testing process.