I suspected that someone has stolen gas from my 1997 Camry twice. I am wondering whether my Camry has an anti siphon valve for the gas tank. If not, is it possible to add one in, and which valve should I purchase?

SOURCE: 1997 Camry Valve Cover Gasket Replacement

Removal of the plenum is pretty straight forward. You will need to replace the plenum gasket after you remove it; the gasket is not reusable. Personally, if I was going to take the trouble to remove the plenum, I would replace the plugs and wires back there, also.
I know, I have a 93 Camry V6, and it is a real pain to do the plugs and wires with the plenum on. There are no secrets or great tips on the plenum removal, just take your time. Remember that there are different size bolts, and where they go. Please get back to me if you need any more info...Hope this helps, and thanks for choosing FixYa to resolve your issue.
The graciousness of a FixYa rating for my assistance would be greatly appreciated.

SOURCE: 1997 Toyota Camry XLE has an overnight parasitic

This should be done with everything turned off and the door closed. with negative battery disconnected. place 12 v test light between the battery terminal and the cable end.(on neg. side) if the light lites up there is a drain. remove one fuse at a time until u see the lite go out. that is the sytem the drain is on. usually glove box light or trunk light or visor light left on or stuck on.