see link
See related link
yes
In the gas tank. I have 2001 Echo.
2001 Toyota Echo doesn't have a timing belt.
http://groups.msn.com/Sorensonbrian/fuelfilter.msnw follow this DIY
See related answers, its already been answered
http://pdftown.com/2000-2002-Toyota-Echo-Service-Manual.html
Look in the trunk, there is cover for the brake light, remove and you will have access to change the bulb.
On a 2001 Toyota Echo, the knock sensor is located on the engine block, typically near the cylinder head. It is usually positioned on the side of the engine, often on the driver's side, and can be accessed from underneath the vehicle or through the engine compartment. To replace or inspect it, you may need to remove some components for better access.
5kg
You have to take out the engine to get to it.