Need help! I almost figured out my fuel tank problem...

[bmx672]

Okay guys, so today was the day I started to tackle the problem with fueling my Boxster (after three summers). I always thought it was the slipped tube flapper problem and didnt want to deal with it. It wasnt the problem. My filler tube is shrouded by a plastic tube in the tank and is not in contact with anything. It free flows from the filler all the way into the tank.
So, that means a vent problem...
The attached photo shows the top of the sending unit. My finger is pointing to the vent. I took the unit out and was unable to blow in or out (I know its a one way). My question is, does that mean that its bad, or are there electronics involved? Im trying to find out if this part is bad regardless if it's plugged in or not to the system. I would think that I should be able to suck air through it...
(I was able to blow through the tube attached to it on the outside by the way.)
Any help is VERY appreciated!

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[Brockmeister]

What exactly is the problem. I'm having an issue as well. Gas gauge isn't reading right. I replaced the entire fuel sending unit yesterday, but it didn't fix the problem. One of the guys on the forum said that it needed to be recalibrated electronically. I'm at a loss as well...

[bmx672]

My sending unit is working properly... I just can't get more than a half tank of gas in my car. I've done all of the obvious things over the last few years... checked the fuse, the tank for obstructions. I'm down to checking the venting system now, but it's pretty complicated. I don't really know the easiest way to do it. I started with the vent from the tank thats in the photo. Not sure how its supposed to work.

As far as your calibration... that might be something a dealer might have to do. Based on what I've read anyway. Anytime I've replaced my sending unit I have not had to re-calibrate it. Not sure what would cause that need?