Hello,
new to owning a 2007 LR3, just got it home and a "check engine light illuminated" UGH!!!
code is PO447 Evaporative Emission Vent Control - Circuit open
the gas tank sounds like water boiling and the gas cap will "burp" and when removed pressure is released.
It has a newer gas cap and the DMTL pump was just replaced. I am speculating that the "purge valve is bad part # MAP500100
please help with any suggestions
Tim

 

Did you ever figure this out? Have the same issue right now after taking truck into car wash and sitting over night in freezing temps. Not sure if that has anything to do with it however; my fuel tank is slow to fill likely because my vent tube is plugged and has been since I owned it but my symptoms are identical to yours... cap pressure and sounds like boiling in tank. I just filled it to the brim too so hope I don't have to drop a full tank in my driveway.