Cadillac Repair: Help, vacuum lines, cadillac deville

Question
I have a 2004 Cadillac deville with the 300HP. Codes 171 and 174 comes up. Those this means the Map Sensor gone bad?

Answer
These codes are oxygen sensor codes that are reading a LEAN running engine which can be caused by numerous things:

missing/broken vacuum lines.

bad gas.
low fuel pressure.


has there been ANY WORK performed on the vehicle prior to this problem ?.