I replaced my gas cap, pulled the battery for 15 minutes, and reset, code came back about 20 miles later.

I read to check the EVAP Purge Solenoid. Not sure how to test this, I felt the solenoid clicking (can't hear it, car is too loud due to custom exhaust)

I did notice that the solenoid is not mounted and is in a horizontal position, I don't know if this matters. At idle it's clicking pretty fast. I unplugged it and rechecked my check engine codes and nothing changed, so could it be the solenoid, or since it's clicking should I check all the lines running to it?

 

Check the hoses that connect to the vacuum switching valve (VSV). There's one hose that's notorious for cracking right where it clamps to a metal hard pipe near the firewall. Mine cracked twice since I owned the car, and I just recently replaced it with a new OEM one.

If you see a crack, you may be able to cut the hose just above the cracked part and reattach what's left. I did that and it lasted me a few years before cracking again.

 

Something else I noticed, the line from the service ports near the purge solenoid is connected to the air intake right after the air filter. Would this pull enough vacuum to pull the fumes out of the tank? I'm pretty sure it was originally on the throttle body. I'll check that line you recommended as well.

Also I disconnect the solenoid and blew smoke through it and smoke came out of the gas tank with both the new and old cap. Is that normal?