P0446 engine code on Solara and 4runner

[yam350yfm]

I have a 2000 Solara 4 cylinder automatic and a 2001 4Runner 4x4 6 cylinder automatic. Both vehicles have the p0446 evaporative emission control system vent control circuit malfunction code, and it happened on both the same day. I replaced the gas caps with Toyota caps and the codes went off for a couple of months. Since then the codes are on frequently. Any suggestions?

[toyomoho]

P0446: Evaporation Emission Control System Vent Control Malfunction.

The computer is detecting one of the below:

When the VSV for the vapor pressure sensor is off there is no continuity between the vapor pressure sensor and charcoal canister.

When the VSV for vapor pressure sensor is on there is no continuity between the vapor pressure sensor and gas tank.

Once the EVAP system has been purged the pressure in the canister is equal to the atmospheric pressure (the system has a leak).

Items to check are a malfunctioning VSV valve for either the vapor pressure sensor or EVAP valve and their wiring, bad vapor pressure sensor, damaged or disconnected hoses, cracked canister, fuel tank overflow valve damaged.

Toyota has a TSB out on some models to inspect the hoses between and pipes between the EVAP VSV and charcoal canister for leaks and replace the vapor pressure VSV and canister.

Suggest starting out by checking the vapor pressure VSV, this is the vacuum valve on the canister and the canister itself.

Overfilling the tank may lead to issues with the canister failing due to fuel.

[yam350yfm]

Originally Posted by toyomoho

P0446: Evaporation Emission Control System Vent Control Malfunction.

The computer is detecting one of the below:

When the VSV for the vapor pressure sensor is off there is no continuity between the vapor pressure sensor and charcoal canister.

When the VSV for vapor pressure sensor is on there is no continuity between the vapor pressure sensor and gas tank.

Once the EVAP system has been purged the pressure in the canister is equal to the atmospheric pressure (the system has a leak).

Items to check are a malfunctioning VSV valve for either the vapor pressure sensor or EVAP valve and their wiring, bad vapor pressure sensor, damaged or disconnected hoses, cracked canister, fuel tank overflow valve damaged.

Toyota has a TSB out on some models to inspect the hoses between and pipes between the EVAP VSV and charcoal canister for leaks and replace the vapor pressure VSV and canister.

Suggest starting out by checking the vapor pressure VSV, this is the vacuum valve on the canister and the canister itself.

Overfilling the tank may lead to issues with the canister failing due to fuel.

[yam350yfm]

I checked the hoses to make sure all were connected and that is all the further I got as rain set so I am on hold for a couple of days until I have some drier whether to work in.

[offroadracer]

And yet another dead end thread.

[Radial GT]

true that ^

I am searching to fix this problem that I also have, and what a bunch of crap.