What term describes an emissions control system or component that is missing, modified, or disconnected?

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

Answer: (D)

Tampering describes any interference with the emissions control system that can reduce its effectiveness. If a component is missing, modified, or disconnected, it shows that the system has been altered from its original configuration, which is exactly what “tampered” implies. This term covers all three situations—the component is gone, it’s been changed in a way that affects function, or it’s been disconnected from the system. The other options don’t capture all these possibilities: “not applicable” isn’t about the state of the emissions system, “modified” is only about changes (not necessarily missing or disconnected), and “missing” only covers absence. In practice, evidence of missing hoses, removed converters, or unplugged lines would be described as tampering because it indicates intentional or improper interference with the emissions controls.