Why does the "check fuel cap" message keep flashing on my 2007 honda accord 4cyl.
Also what does code B 12 mean on the same accord?

Is your fuel cap tightly affixed?

If you don't turn it adequately (most require 3 clicks) it won't be tight enough.

Fuel system is pressurized, inadequately tightened fuel cap tells the computer there is a pressure loss.