Seafoam is a cleaner, you have an O2 code. Let's address the fact that your pcm is dumping fuel which will screw your cat in quick time if you don't fix the problem at hand. And this problem... won't be fixed with seafoam.

Why is the O2 not working? Check for voltage at the connection, if it's there.. check that the wire didn't get burned or something and then get that new sensor in there.