How long does a smog test usually take?

A smog test usually takes 15 to 20 minutes for BAR OIS used on cars model year 2000 and newer equipped with OBD II and between 20 to 40 minutes for the older cars depending if Evaporative testing is required (cars olde r than 1995) . However, you can significantly reduce your wait time by buying and scheduling your appointment online in advance. This ensures a faster in-and-out service with minimal delays.