On my 04 GTO and two others we have upgraded the fuel pump in....all 3 or 100% have had a kinked hose feeding out of the tank....
Here is what all 3 looked like...
http://img.photobucket.com/albums/v6...uelbucket4.jpg
We replaced them with good ol blue hose...voila...higher fuel pressure and even flow...
http://img.photobucket.com/albums/v6...uelbucket3.jpg
Dont know about the 05/06 cars...but if you have a 04...crawl under there and look....if you have a kink...replace it....