P0456 Code

My 2003 Ram 1500 (4.7 litre with approx. 61,000 miles) recently threw up a check engine light which my local Auto Zone read as a P0456 Emission Control Evaporative Leak. The guy at A/Z told me this indicated a very small leak and suggested checking the gas cap. It seemed to check out just fine but after he reset the code, it came back up again after a couple of weeks driving. Other than that the truck runs great. Should I just replace the cap and see if this corrects the problem?
Any suggestions would be much appreciated.

Thanks - T-bank

I personally would heck the ags cap is only a few bucks and if it don't fix it at elast you would have an extra laying around when you need it.

I've heard of some of the lines on the fuel tank cracking. I would take a look under there as well.

Thanks for the input. I picked up a new gas cap last night and will put it on tonight. I also plan on checking out all the vacuum lines.
I'll let you know how this works out.

Found a hose on the vapor recovery tank cracked pretty badly. I replaced the hose and the gas cap and disconnected the battery to reset the check engine light. So far, so good.

Another thread mentioned the rubber around the fill port to the tank was cracked from the gas fill nozzle. A place to look. That person replaced the cap three times before finding this crack.