What will occur if a vehicle is not equipped with an OBD II system?

If a vehicle is not equipped with an OBD II (On-Board Diagnostics) system, it will typically undergo a tailpipe emissions test instead of the OBD II test that is standard for vehicles that are equipped with this diagnostic system. The OBD II system is designed to monitor the vehicle's emissions control system and can provide real-time data to inspectors about the health of those systems. When a vehicle lacks this system, inspectors revert to traditional methods of checking emissions, which involve measuring the exhaust gases emitted directly from the tailpipe during a test.

The other choices involve situations that do not accurately reflect what happens when a vehicle is not equipped with OBD II. The vehicle does not receive an exemption from testing or just a visual inspection but is required to undergo alternative types of emissions testing, emphasizing the importance of ensuring that vehicles meet environmental standards regardless of their diagnostic capabilities.