Dont bother changing your PCV valve. Just clean out the EGR chamber, not just the EGR valve. Chances are thats your remaining issue, hence the MPG reduction 6 months later. You can clean them both out with carb cleaner. The EGR chamber is located under the fuel rail. Below is a link to someone on HondaTech.com who cleaned out theirs. Thats pretty much how mine looked as well. Make sure to clean out those ports as well. The whole job shouldnt take more than 1.5 hours, maybe 2 for the less experienced DIYer..i cant wait to see you results maybe i need to change my pvc again its been awile. i bought a brand new egr valve about a year ago and thats when my mpg jumped up to about 45 on average but then it dropped back down about 6 months later to what it is now. how did you clean out the egr valve? i still have my old one maybe i will clean it and test and see if it helps
http://honda-tech.com/showthread.php?t=2151691