ok so my tc is just bout to hit 90000 miles and the check engine light came on.. i went to advanced auto parts to check the code.. and the guy said it was the downstream o2 sensor... called around to get a price .. toyota was 170, advanced was 155, and called another shop and found it for 102... where is this o2 sensor??? any pics? i know the ones in the header... and im assuming the other one is somewhere underneath, hence the "downstream" ?

secondary o2 sensor (downstream o2) is located on the s-pipe

http://www.scionlife.com/tech/manual/image.php?image=tc05/tc05_1353.gif

if your going to do this yourself, make sure to do it after it has parked overnight and use a lot of lube, and the correct O2 sensor socket is a huge plus especially if its really rusted down there.

anyone know a link or website where i can get this cheap?