Will it run at all or always starts and stalls?
Does it hold fuel pressure when you shut the key off?
Is the check engine light on you probably have a load of codes stored but there may be something there that will put you on the right path.
Fuel pressure is with in specs even the 3-10 drop once running
Might try unplugging the map sensor to see if it runs better unplugged .(unplug the electric plug)
Also see if the EGR valve is stuck open.