Fuel Tank Overpressure?
 

2006 LR3 4.4. Since taking to the car wash last night and giving it a thorough bath; including the undercarriage my gas tank now has a pressure build up. I went to fuel up today and when I opened the cap it had a decent amount of pressure behind it. Brought it home checked and cleared codes (no engine codes) I opened the tank while it was running and it sounded like it was bubbling inside the tank. Any ideas on this one? I've searched around the internet but nothing real specific other than possible evap stuff... not real familiar with those components. Its below freezing where I'm at so thought maybe with the massive water blast I may have froze up a breather or something.. no clue. Any help would be appreciated.

N/M.. resolved itself for now.