X260 P0456 code

2016 XF 3.5t awd. Any clue where to start looking? I did get a gas cap warning a few days ago, which was odd. No obvious signs of a leak anywhere. Any input is appreciated.

Off the top of my head I recall that being the code for EVAP system large leak. Is that correct?

If so, most mechanics will tell you to just go ahead and replace the gas cap. It costs almost nothing to give it a try and oftentimes fixes the problem. If that doesn’t do it, you’ll need to follow the vacuum line from the intake back to the gas tank looking for anything disconnected, cracked hoses, etc. If you still can’t find it, you’ll probably have to take it to a mechanic and have a smoke test performed to find the leak.

It’s a code for a small leak. It could be the gas cap, but when I bought the car 2 years ago, the dealer ordered a new gas cal since the tether was broken on the original. For $50, it may be worth it to try before o start taking things apart.

Ah, that could be. I must be thinking of a P0455. Still not bad for not looking it up… actually kind of sad in a way.

Yes, I would definitely try replacing the gas cap first if its two years old. You can visually inspect the seal on it too, but its hard to know for sure. You can always buy an aftermarket cap if you don’t want to fork out $50 for an OEM one.