A grounded signal wire from pcm, faulty pcm, or faulty injector are the only possible causes.
A bad ingnition module, Are a bad computer.
the deville is famouse for computer problems, once the car is started the brain sends a signal to the injectors to puch out an introductory supply of fuel for startup, basically this signals tells the injectors how long to stay open, perhaps the signal is telling the injectors to stay open too long or too much, good luck.
Constant ground signal from the ECM, or injector could be faulty and stuck open.
"Are you open to hosting a friend at your place?"
it depends on which walmart, cause some stay open for 24 hours and others stay open till 9:00 or 10:00.
The alternator is failing.
No. Some tornadoes stay in open fields and don't cause any damage.
witch lights
basd fuel
A thermostat
The radio time would stay on if you had the keys in the ignition but the ignition was only turned halfway.
Try cleaning your injectors.