What is this?

[its turbo time]

I was looking underneath my car by the gas tank and there is this large oil filter looking thing that says "AC spark Plug" hanging in front of my gas tank with lines attached on either sides. Is this some kind of fuel filter?

 

[1QuickGN]

Probably an aftermarket fuel filter. I think a Buick shop in St Louis installs a lot of them on GNs.

 

[its turbo time]

Where would i get a replacement for that?

 

[1QuickGN]

I think Bill at Buick GN\T-Type Performance in High Ridge Mo has them. I would think any parts store could interchange to a differant brand.