What testing system has been utilized for vehicles from 1996 onward since 2004?

The correct choice is OBD-II because it refers specifically to the on-board diagnostics system that has been in place since 1996 for all vehicles manufactured from that year onward. The OBD-II system is designed to monitor the performance of the vehicle's engine and its emissions control systems. It provides a standardized diagnostic interface for vehicle emissions testing and troubleshooting, helping to ensure that vehicles meet both state and federal emissions requirements.

OBD-II has been essential in modern vehicle diagnostics and emissions control, as it allows for real-time data collection and monitoring of engine parameters. This system generates diagnostic trouble codes (DTCs) that indicate any issues with emissions-related components, facilitating timely repairs and maintenance. Additionally, it plays a critical role in the Inspection and Maintenance (I/M) programs as a key component for assessing vehicle emissions compliance.

While Inspection and Maintenance (I/M) is a broader program that includes various methods of vehicle inspection, the specific system utilized for vehicles manufactured from 1996 onward is OBD-II. On-board diagnostics (OBD) also refers to vehicle diagnostics more generally, but it is the OBD-II standard that has been in use since 2004 for emissions-related testing, making it the precise and correct answer. The Vehicle emissions testing