One problem related to gas recirculation valve (egr valve) has been reported for the 2004 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota 4Runner based on all problems reported for the 2004 4Runner.
My Toyota 4 runner smells like rotten eggs. The dealer tried to replace the catalitic connverter and it still smells.