Catalytic Convertor problems of the 2003 Toyota Sienna

August 24, 2003 subject: sulfur odor from exhaust enters passenger cabin compartment (this is what the dealer says the problem is). I have a model 2003 Toyota Sienna that has a burning/sewage smell, which the dealer calls a rotten egg smell, entering the inside of the car. This usually happens when accelerating with the air on or off. My dashboard air switch is always set to re-circulate interior air (not to bring fresh air from the outside in). The smell gets so bad that I must open the windows to air out the stink. It happens no matter what octane of gas I use. It may happen or not happen at any given time. I frequent gas stations near me that are no older than two year old. When I brought in the van to a factory Toyota service dealer and after they checked it out, they told me that this problem is normal with all Toyotas especially Siennas & sequoias. They handed me a technical service bulletin (TSB) entitled " sulfur odor from exhaust" all models, document number eg003-03. I have not been able to find TSB this on your site or any other internet site. This may be normal to smell at the end of the exhaust tailpipe, but should the smell of sulfur be getting into the passenger cabin area with the doors & windows closed and the air on re-circulate? should it be so strong that it forces the occupants to open the windows to get fresh air in the car? why is sulfur odor that is a component of gas exhaust entering the car? how safe is this for us, kids, and infants? should not my vents and windows being closed, prevent this smell from entering the passenger area? the dealer says no, but my closed vents keep out other cars' exhaust, even if they are burning oil and making white clouds of exhaust in front of us when we are driving behind them. Please respond. We hope you can help us. Thank you, frank autore & family.