I have a 03 Tribute 4WD, 4cyl,5 sp. There seems to be a very slight hesitation around 25-35 MPH, the Check Engine light came on, and the following code was retrieved:

P0456 Evaporated emissions systems leak detected (very small leak) ON 2 Evaporative.

I was toldthat this is usually a loose or faulty gas cap issue. I replaced the cap with a new one and reset the system,the slight hesitation continued, and After about a week the light came back on, Ichecked it again and found only the same code as before.

Prior tothis I had a sticky throttle body, I sprayed it with carb cleaner to remove all the gummy deposits, I also changed the air filter and spark plugs, and wires. Have not replaced the fuel filter.

Any ideas??