You people only see what you want to see and hear what you want to hear. You have your answer right below here. I don't know why I even care, you won't even listen. You deserve to have your light on. Good luck.
What is the code now? On the left side of this post is a place to look things for some good information. Under encyclopedia you will find the 'exhaust & emission' labeled, and click on that for information about the EVAP system and the operation of the components. Just because it called for a vent valve, does not mean the vent valve is the problem, you have another problem that needs to be diagnosed. I f you will google p0449 Ford explorer, there is a listing for a RepairPal article on the complete understanding of this code and the proper way to consider the fault code. Good Luck.
Trying to look up the code in Mitchell P0449 for a 2003 Mountaineer shows it to not be plausible. Is there a typo? Other cars can set that particular code and it would be a vent solenoid "circuit" issue. Which would be correctly tested by checking for power to the solenoid, and then using a scan tool bi-directional controls to prove that the computer can turn the solenoid on. The second diagnostic event "na 01/01" has to be a scanner issue. You may want to try a different tool.
I was there before, and know the code does not exist for the Ford line. When I stated that, I was told to google it, and there is information on the Ford line, so that's why I asked them to find this information so they could get an idea that the vent solenoid is not necessarily the fix.