Help !!!...P0171 code on 2001 S40
 

Does anyone know where do I start in order to check these Vacuum Leaks? I have been working and eliminating issues by replacing the MAF and other sensors on the car and I am just down to this Vacum Leak which definetly has to be the problem. The car does stall every once in a while and is consuming a lot of fuel than normal. Please help!