I have a 2000 Camry with 86,000 mi the check-engine light came on 4 days ago.

It has come on intermittently in the past and then shut off itself.

This time it hasn't gone away. A Code reader shows P0446, I have researched the code and found this; What does OBDII code P0446 Evaporative emissions control vent circuit low mean? I read one of the potential fixes for this was a loose/malfunctioning gas cap - so I tightened the stock one and made sure it was tight.

That didn't fix it, so I bought a new gas cap and tightened ... still didn't fix it.

With that said, I have two questions:

  1. Does anyone know what else I may need and a rough guesstimate of how much it would cost?

  2. Additionally, does this fail you on inspection?

    Engine: 4 cylinder, automatic transmission

It will need to pass inspection in Pennsylvania, USA

  • after replacing the gas cap did you have the fault code cleared?
    – cinelli
    Apr 12, 2013 at 2:42
  • Your second question is too localised - Inspection requirements vary wildly from country to country (and often state to state in some countries), so we can't tell you if it'll fail unless we know which inspection it needs to pass...
    – Nick C
    Apr 12, 2013 at 10:13
  • i used my own OBDII scanner and cleared it myself yesterday - it is gone now. We'll see if it pops back up
    – CodeTalk
    Apr 12, 2013 at 11:31

3 Answers 3


There are a lot of things that can set this code, so it can be time consuming to figure out, and there are some special tools that make the job a lot easier. You can do it without the special tools, it's just going to take longer. The list below is what it takes to set the code.

  • When VSV for pressure switching valve is ON, ECM judges that there is no continuity between vapor pressure sensor, fuel tank and charcoal canister (2 trip detection logic)
  • When VSV for pressure switching valve is turned OFF, pressure in fuel tank is maintained at atmospheric pressure (2 trip detection logic)
  • When VSV for CCV is ON, pressure in charcoal canister and fuel tank is maintained st atmospheric pressure (2 trip detection logic)

Basically anything leaking vapor inside the dotted line in the picture below will set the code. Check all the hoses represented in the picture below for leaks.

enter image description here

Any of the three valves could be bad as well, and can be checked with a DVOM.

I have found more info here


Answers like the above one that suggests you replace something before checking something are usually a very expensive way to fix your vehicle. Check for leaks and circuit correctness before replacing a charcoal cannister.


replace charcoal canister under gas tank. if this doesnt work then check hoses for leaks. ( use a smoke machine )

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