My 2001 4runner 4x4 has the following problem

VSU off, VSC Track, and Check Engine lights are on. I have replaced the gas cap and seal.

I checked Engine codes using the reader at Auto Zone and got the following:

PO440 Evap Emission control system
PO441 Evap Emission control system Purge Flow Fault
PO446 Evap Emission control system Vent Circuit malfunction




I found these other items listed below as possible corrections on other posts on this list and wanted to ask those who have had problems with codes PO440, PO441, and PO446 what they did to correct their problems


Hose or tube cracked, holed, damaged or loose seal.
Fuel tank cracked, holed or damaged.
Charcoal canister cracked, holed or damaged
Vapor pressure sensor
ECM

There are so many vac hoses, how do you find one with a small leak?
Fuel tank cracked? charcoal canister cracked? Hole or damaged vapor sensor? How do I check for this?
What is ECM?

I think I will need to buy the manual but wanted to ask for advice first.

Thank You
Don