Hey Scotty, I have a 2012 Acura TL Base 3.5L automatic transmission and have had trouble with my check engine light coming on repeatedly with codes P0455 and P0456. If I reset the code maybe a week later or so the tighten gas cap message will come on then turn off after about a day or 2 then a couple days after that the check engine light will come on.  I have had smoke tests done by multiple repair shops and no leaks detected and had it taken to the dealership to see if it needed any software updates but everything was good. Parts that have been replaced are new gas cap, evap canister vent valve, canister purge valve, charcoal cannister, and fuel pressure sensor. If you have any advice on what could be wrong I would greatly appreciate it. Thanks.