Why is my 2007 Acura MDX check emission system light on?

One of the most common reasons the check emissions system light will come in the 2007 (or any) Acura MDX is, believe it or not, a loose fuel cap. The reason this is the case is because the fuel system uses whats known as a positive vapor recovery system. If the cap isnt secure, pressure escapes the tank and triggers the light to come on. Because the system is emissions related, it will trigger that particular warning light. If tightening the cap doesnt work, some of the other causes could be from a leaking gas tank due to corrosion or some kind of puncture. If not the tank itself, the fuel hose might have a loose clamp, or it would be cracked.