2009 Hyundai P0026, P0012, P0028, and P0022 Fault Codes: Causes and Solutions

My 2009 Hyundai was repossessed and left unsecured in the lot for three days. No oil or engine warning lights were on when it was returned. An oil change had been completed one week prior. While driving home, both the oil and engine warning lights activated. The vehicle has fault codes P0026, P0012, P0-28, and P0022. Are these codes related to a single underlying issue? What could have caused this? Additional details: the car had approximately one-quarter of a tank of gas and was in use during pickup.