One problem related to catalytic convertor has been reported for the 2004 Subaru Forester. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Subaru Forester based on all problems reported for the 2004 Forester.
Excessive sulfur dioxide odor (rotten egg). Company refuses to fix converter, blames fuel. Converter should handle the sulfur content of fuel, regardless.