Feed validation error

I put my client’s blog’s feed through feedvalidator.org but am getting a few errors.

http://feedvalidator.org/check.cgi?url=http%3A%2F%2Floveanddating101.com%2Ffeed%2F

Is there a plugin that can automatically replace the html codes or texts that is causing trouble to another text? It’s a self updating blog which pulls content from feeds, so I’m looking for a plugin that automatically changes certain html codes when it detects one.

I’m using Word Replacer but it doesn’t seem to be working.

Any other methods to solve this problem would be appreciated too. Thanks.