CODE PO446 Help

[lightrunner]

Im getting PO446 code and have changed most of the vacumme lines. I was wondering if any on else has been able to clear this mess up. Weird.....Only happens when there is a drastic change in the temperature or barometric pressure. There are several things that can go wrong here but some are very expensive (canaster $400 and up) and others not so much. Any Ideas?:redbrick:

 

[jgue467]

P0446 = Evaporative Emission Control System Vent Control Malfunction

From our beloved FSM here is the list of items to check (in most likely order):

1) Vacuum hose cracks, holed, damaged or disconnected ((1), (4), (5), (6) and (7) in Fig. 1)
2) Open or short in vapor pressure sensor circuit
3) Vapor pressure sensor
4) Open or short in VSV circuit for EVAP
5) VSV for EVAP
6) Open or short in VSV circuit for vapor pressure sensor
7) Charcoal canister cracks, holed or damaged
8) ECM

Oh - don't forget to check your fuel cap, make sure seal looks good and its on snug.

FSM located here: http://www.toyota-4runner.org/3rd-g...faq-tutorials-documentation-reference-v2.html

Luck!

 

[drmoreau]

ugh, I get this one as well, along with the p0441 and p0440 as well. truck runs fine, but I think it might be why I smell a slight gasoline smell every time I turn the truck off or if I'm sitting at a light for a while.

 

[lightrunner]

Ive been doing some reading on this and have seen several fixes, attempts, questionable fixes and so on... Looks like the VACUUM SWITCH part #90910-12198 (Switch at the Canaster by the Gas Tank) is the average winner to this problem. I think I might try it. Any thoughts on this from former Victims?