Hello. Tonight, I solved the mysterious poor radio reception in my 04 Odyssey and I thought people here should know it's an easy fix. At the bottom of the center console where the 12v power plug is located, behind this, is the radio antenna plug, which had simply come unplugged causing poor FM and zero AM reception. The plug is where the feeder cable from the radio plugs into the long cable that goes to the fender antenna mast. Removal of the console bottom side panel on the right is required. I plugged my antenna back in and used electrical tape to ensure this will not happen again. I hope this helps somebody else who has been having similar issues.