What information does the OBD II system provide to inspectors?

The OBD II system, which stands for On-Board Diagnostics II, is designed to monitor the performance of a vehicle's engine and emissions control systems. It provides inspectors with critical information through the use of diagnostic trouble codes (DTCs). These codes are generated by the vehicle's computer when it detects an issue related to emissions or engine performance. The presence of these codes is a primary indicator of malfunctions that could lead to excess emissions, making it essential for emissions testing and compliance.

The advantage of using the OBD II system is that it provides real-time data on a vehicle’s performance, allowing inspectors to quickly identify whether a vehicle meets emissions standards or if it has underlying issues that need to be addressed. Understanding these codes helps ensure that vehicles are running efficiently and not contributing unnecessarily to environmental pollution. Other options such as ownership history, repair cost estimates, and vehicle age and mileage do not pertain directly to the emissions status or performance as indicated by the OBD II system.