This morning my check engine, vsc off, vsc trac lights all came on. Wen to Autozone and this is what code popped up-

P0446 Evaporative Emission Control System Vent Control Circuit Malfunction

Now what do I do? Any fixes?

Thanks,

ScottDetroit

I have the same issue (2001 SR5 Sport, 3.4 - auto). Luckily I have the stage II computer, and can reset the codes, so I've been playing around. I received the lights with the the exact same code for about a week. I then filled the gas tank, and ensured I twisted my gas cap around about 3 full times and reset the codes. The lights stayed off for approximately 100 miles and 10 driving sessions. Once back on, I reset, and now they are coming back daily.

My gas mileage is suffering just a bit (but not horrible, I'm currently averaging ~15 MPG, all city driving - was ~17MPG city before the issue).

I've read lots on this site and other forums, and there are many potential solutions and trouble shooting advice. The code, if alone, seems related the VSV (part cheap ~$80, labor not bad or easy if you are mechanical). If you have to do the canister or replace vacuum lines, the cost goes up exponentially.

I'm personally holding off until I do more research or find the time to start testing the system. I'm open to suggestions if anyone has a tried and true solution (especially those awesome Toyota techs that are lurking around).
- Drew