In the gas tank. I have 2001 Echo.
take it to the Toyota dealership and ask them to replace it
According to my reference, there was no 2004 Toyota Yaris but there is a 2004 Toyota Echo. (The Yaris replaced the Echo in 2006). See sources and related links below.
For my 2002 Echo it is 3.7 Liters with a filter change.
3.5 liters
when it breaks
about $1500 AU
Inside the fuel tank.
It is conveniently located inside the fuel tank :)
$1500 to $2000
You can replace your 2003 Toyota Echo antenna. Remove the antenna retaining nut. Remove the cable from the bottom of the antenna. Reverse the process to install the new antenna.
http://groups.msn.com/Sorensonbrian/atfchange.msnw