never heard of a fuel trap before, nothing on my ecu vac pipe?

why would there be a fuel trap on a pipe that carries air?

Tony is right on what he says about the fuel ecu it hasnt a clue on what boost the car is running, it just have, lets say programs on it to evaulate what the sensors are telling it i.e Cold Start enrichment, Throttle opening, Full load, overrun and also a fuel cut