If your vehicle has power locks, it will have the delayed locking feature.
This feature will delay the actual locking of the doors for up to five seconds when the power door lock switch or remote keyless entry transmitter is used to lock the vehicle.
If any door is open when locking the vehicle, three chimes will sound signaling that the delayed locking feature is active. Five seconds after the last door is closed, all of the doors will lock and the turn signal lamps will flash. To cancel the delay and lock the doors immediately, press the lock button a second time.
This feature will not lock the doors if the key is in the ignition.
You can disable this function through the Driver Information Center (DIC). See DIC Vehicle Personalization.
Chevrolet Cobalt Service & Repair Manual. Emission Control System Inspection
Caution: Do not remove any
component of the engine emission control system. Operating the engine without
the engine emission control system intact will reduce fuel economy and engine
ventilation. This will weaken engine performance and shorten engine life.
The vehicle ...