I am new to this forum, hello everyone! I have recently retired and now have more time to do the things I really want to do. I have recently rebuilt basically the entire emissions related systems on my 1997 Toyota Avalon XLS. The replacements are as follows. New EGR valve, new EGR position sensor, EGR new vacuum tank, new EGR vacuum switching valve, new charcoal canister with switching valve, new gas cap, new vapor sensor, and all new vacuum hoses throughout with nylon hose claps to remove all possibilities of leakage. I also replaced all 3 heated O2 sensors and the catalytic converter. The only thing I did not replace was the EVAP vacuum switching valve because when testing it appeared to be OK.

Now I am getting the P0446 - EVAP emission Control System Vent Circuit Malfunction. Of course the CEL is on again! I am feeling bit frustrated, can anyone suggest their opinion or experience related to this problem? Any help or comments will be greatly appreciated. I guess the real question is how to get the evap system charcoal canister to purge. Thanks in advance for your help.

Sir I was just wondering how much of a bear it was to change out charcoal cannister. I am throwing same code and it looks to be in a real tight area.

Here is some info that should help.

I replaced a few items along with the char. cans($200 and 10 mins).
The code returned...grrr Could have saved $ if I'd known the following.

To pass smog, simply clear the code, drive about 10 or so miles for enough of the
system to reset and pass.

Glad I didn't go on spending like the OP. The dealers will charge $600+ to replace
the Char. cans!