One problem related to other fuel system tank filling/charging has been reported for the 1999 Toyota Sienna. The most recently reported issues are listed below.
Both air to fuel sensors went in the fuel emissions part of the engine. My check engine light came on. I had to replace both the sensors. The part replacement for each was $375. 42 not including the labor. The parts had to be replaced to pass state inspection because it caused the check engine light to come on. It is an expensive piece that should be covered under the emissions warrenty, but is not. Dt.