Yes, that is the exact part I am referring to. It has been debated whether or not boost causes this part to malfunction, but I can tell you with absolute certainty that it does. The inner thin rubber diaphragm is only meant to see vacuum pressure. It sits on a shaft that has 4 protruding sides to it for rigidity, like a cross pattern. When the diaphragm sees boost and flexes the opposite way it is designed to, towards the four sided shaft, the square edges of the shaft eventually wear it down and will tear it. When this happens the seal is shot and you will throw codes for an EVAP system leak. It happened to me, and as soon as I diagnosed the problem and replaced the valve, the CEL went off and has not come back on since.

You do not have to drop the fuel tank. Just jack up the back of the car and you will see the valve situated right behind (towards the back of the car) the fuel tank. Pull it out of its clip, remove the four hoses, and replace it.

Let me know if this does the trick.