Since you live in a metro area where I'm sure lots of salt is used in the winter, what about rust around the filler neck where you put gas in? Also, what mehullica said.
After all my parts throwing at it, this was what I suspected.
Finally caved in and took it to a shop to smoke it, turns out there was a rust hole at the filler neck.
$250 dealer only part and 3 hours to R/R.
A little out of my capabilities at home to drop the tank a little to get to the area.
I would get a smoke machine but i also need to invest in a scantool with di-directional controls to turn on/off the purge valve as well. I realized this as i was about to order up the smoke machine linked on amazon.