I have a b5 a4 1.8t auto. I was looking unde my car and noticed on the passenger side by the gas tank there is a metal cylinder barely hanging there and was wondering what it could be? It is worrying me so I am curious to what it is and how to fix it. And also when I push up on the can thing it makes a hum/ vibrate sound? Any comments help. Thanks!

 

Fuel filter maybe?

 

Maybe? I was thinking maybe brake booster but didn't know?

 

I crawled under the car last night and it is the fuel filter. The cheap *** bracket broke and so there is nothing holdIng it. So I ziptied the bracket on and need to go to the store and buy the right bolt. Thanks

 

When most people change their fuel filter they find that the bolt is seized and end up cutting it to get the fuel filter out of the bracket. Then they just zip-tie the bracket closed. That's seems to be good enough to keep it from going anywhere and lasts a while so you shouldn't have to worry about it.

 

^This. I didn't even do that much. If you put the filter back up before you take the pry bar off the tank, it won't go anywhere. If you whack something hard enough to dislodge it, you're gonna have bigger problems on your hands anyway lol