Unknownpolish

I know this is an old thread but i am having the same issue with my cobalt, had the tune for a couple years, ended up replacing the gasket valve cover because it blew but made the mistake of not disconnecting the battery when removign all the wires and now the car wont start, i was informed could be because it needs a relearn but mine is automatic so dont know if there is a diff way to do it then they advice on zzp.