What should inspectors do if they suspect an aftermarket part is affecting emissions?

When inspectors suspect that an aftermarket part is affecting emissions, it is crucial for them to inform the vehicle owner and advise them of potential non-compliance. This is important because aftermarket parts may not meet the original equipment manufacturer (OEM) specifications and could lead to increased emissions, which can violate environmental regulations. By notifying the vehicle owner about the implications of the suspected part, inspectors not only ensure that the vehicle adheres to emission standards but also provide the owner with the opportunity to address any issues that may fall out of compliance. This proactive communication helps in maintaining air quality standards and encourages vehicle owners to seek compliant alternatives.

The other choices do not align with the responsibilities of an inspector. Ignoring the suspected part neglects the issue that could contribute to pollution, while replacing the part on the spot could cause liability or misinterpretation of the inspector's role. Proceeding with the emissions test without addressing the concerns about the part could yield misleading results, making it crucial to address any potential issues before continuing with the testing process.