One problem related to catalytic convertor has been reported for the 2007 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Toyota Sienna based on all problems reported for the 2007 Sienna.
Catalytic converter emits strong sulfur odor into passenger compartment. The smell made my family sick with headaches. Toyota reps told me to note what gas station I go to and it may take multiple visits to fix since no one else reported similar problems.