I changed the oil and filter and now im getting "engine oil low add oil" message. I added 6 qts if 5w30 synthetic. I know the car has oil in it. but this baffles me. any ideas?

 

Which engine ?

There must be a sensor . This shows the o-ring .

2014 BUICK LACROSSE 3.6L V6 Oil Level Sensor Gasket / O-Ring | RockAuto

Also , check the diagram .

GM OEM-Oil Fluid Level Sensor 12639127 | eBay

I would first try to locate the sensor . Apparently on the oil pan . See if you accidentally disturbed the sensor ot its wiring . When you changed oil .

You might try disconnecting the - battery cable for a few minutes in hopes you can reset the electronics .

Best of luck :-)
Wyr
God bless