Cadillac CTS Owner's Manual page 205

Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have
or may begin programs to inspect the emission
control equipment on your vehicle. Failure to pass
this inspection could prevent you from getting a
vehicle registration.
Here are some things you need to know to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
check engine light is on or not working properly.
Your vehicle will not pass this inspection if the
OBD (on-board diagnostic) system determines that
critical emission control systems have not been
completely diagnosed by the system. The vehicle
would be considered not ready for inspection.
This can happen if you have recently replaced your
battery or if your battery has run down. The
diagnostic system is designed to evaluate critical
emission control systems during normal driving.
This may take several days of routine driving.
If you have done this and your vehicle still does
not pass the inspection for lack of OBD system
readiness, your GM dealer can prepare the vehicle
for inspection.
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