When I pulled my intake last month I did not pull the purge solenoid tube from the firewall side, I just left it connected and positioned out of the way.
Ended up popping a P0455. Gross evap leak.
I am assuming that as I was moving the tube around as I was working, the tube and fitting seal broke. And instead of rotating around the oring, the tube was rotating around the fitting. New tube fittings do not rotate and old tube fittings do. New tube installed, and codes cleared. We shall see if that fixes it.
Additionally , and this may get lost in the ethos, there are 2 different part numbers for said tube.
12578233 - 99-02
12575527 - 03-07
The difference is about 1/16" diameter on the firewall side, 03-07 being larger. Not sure is this is common knowledge or not.