Gasoline motor vehicles are tested to determine if they meet one of the following requirements:

(1) Two-speed idle exhaust emission test standards:

(2) Instead of a two-speed idle exhaust emission test, ecology may require a 1996 or newer model vehicle be tested using the vehicle's on-board diagnostic (OBD) system. To pass the OBD test:

(a) The check engine light must not be commanded on while the engine is operating.

(b) The emission related monitors must have completed their checks and be ready to report potential problems, except:

(i) A 2001 or newer model year vehicle may have one monitor not ready to report.

(ii) A 2000 or older model year vehicle may have up to two monitors not ready to report.

(c) For the vehicle to pass a retest, the monitor(s) that commanded the check engine light on during the initial test must be ready to report.