2010 Toyota Sienna Owners Manual - Page 192
2010 Toyota Sienna Manual
Page 192 highlights
2-1. Driving procedures CAUTION ● The exhaust should be checked occasionally. If there is a hole or crack caused by corrosion, damage to a joint or abnormal exhaust noise, be sure to have the vehicle inspected and repaired by your Toyota dealer. Failure to do so may allow exhaust gases to enter the vehicle, resulting in death or a serious health hazard.