P0455 …didn’t need a smoke machine for that one

What the berking berk berk?  :-)

Here's my mother in law's ultra low mileage (20k) '12 Silverado.  It's had a CEL for about 5 years but nobody ever bothered to fix it because it ran great.  They did the gas cap shuffle and it didn't help.  Well, we borrowed it to haul some stone and I finally couldn't take it anymore.  Threw my scanner on it and P0455 Evap Large Leak.  Crawled under it and low and behold there it is...

That line going to the charcoal canister is gone! What would have caused that?  I'd guess maybe rodents but then why did they not eat anything else?  

Sure looks like rodent nibbles.  Maybe they decided it didn't taste very good and moved on to greener pastures (although having said that, one time squirrels ate the plastic gas tank off my lawn mower, so apparently gas fumes don't turn them off.)

I had a similar problem on my Civic due to sitting outside for nearly a year, had the hoses fixed, but a discontinued solenoid near the gas tank seems to be the issue and still tripping the code ugh.