(a) A vehicle shall fail the OBD test if it is a 1996 or newer vehicle and the vehicle connector is missing, has been tampered with, or is otherwise inoperable.
CFR 40-85.2207-2014 history
2014CFR 40-85.2207-2014 Protection of Environment. Part85:Control of air pollution from mobile sources. Section85.2207:Onboard diagnostic test standards.