Just got this CEL code P0174. Vehicle is a 2013 Acura MDX. It's running fine. Not sure if anything to do with fuel, happened not much after i fueled up. Got an initial SWD (all wheel drive) error displayed, but that went away. When i toggle thru the display when driving, shows AWD system engaged and applying to each wheel through accelerations, I think that is operating fine.Vehicle has 81K on it, drives fine. What have you all expierenced with this CEL code of P0174, and the most likely cause and fix?

 

most likely vacuum or exhaust leak, but could be much so much more reasons for this CEL...

 

Code cleared by itself. Just came back now about 3500 miles later. Anybody got a clue where to look. No exhaust leaks.