An emission control system or component that has been replaced with a component not marketed by its manufacturer for street use on the vehicle.

• A. Not Applicable
• B. Modified
• C. Tampered
• D. Missing

Answer: (B)

When an emission control component is replaced with something not marketed by the manufacturer for street use, the system has been altered from its original configuration. This situation fits the label Modified, because it indicates a change to the built-in emissions setup by installing a non-OEM part that isn’t approved for normal street operation. It doesn't necessarily imply intent to defeat emissions (which would be Tampered), nor does it mean the part is entirely absent (Missing) or not applicable to the vehicle (Not Applicable). So, the best way to describe this scenario is that the system has been Modified.