95 neon code help, codes 31 and 12

[zooyork182]

tonight i was coming home and my check engine light came on, i check it and its code 12 and 31. does any one know what they mean and how to fix these problems. for code 12 i disconnected my battery so long a go and it never came on. i put new wires in during the summer, i drove the car fine. also i dont know what the evap purge flow monitor is or evap solenoid circut is. are these problems serious? is it still safe to drive my car? and help would be great.


thanks