[MENTION=25593]99'HEARTBEAT[/MENTION] - Just wanted to say a big Thank You for the assitance and write up. It is yet another example of the of the quality of fine people who are at this site!
Here's the back ground and the latest on my situation. Late last week my warning system came on with a loose fuel cap message. I pulled over and although it was secure gave it another good twist. Over the weekend my truck showed the P0449 code. Hence, my first message. Between chasing parts that didn't fit gave my fuel cap another couple of checks. Yesterday, out of curiousity, I cleared the code and ran a bunch of stop and go type errands. Once a gain I received the loose fuel cap message. And once again, found it to be tight and gave it another shot of tightening to be sure. I've put on close to 50 miles on the truck since I cleared the code without receiving another CEL. After checking; my original valve positioned by the fuel tank, was replaced about 4 years ago while the truck was under warranty. After talking with a trusted mechanic, it appears that if the CEL come on again with the 0449 code, it would be advisable to repalce the valve that is on the intake manifold.