Hello all! I picked up an ES a few months ago and it came with a a p0446 evap code that was setting a CEL. I searched around and found that a bad gas cap is a common cause for this code. The gas cap on the car was a non-oem replacement (I don’t think it was sealing properly) so I recently switched it out for a Toyota one. I cleared the code and no longer have a CEL but I’m still getting a p0446 pending code. Every 75 miles or so the VSC and VSC OFF lights come on and only reset after turning the car off and on.

Do I need to complete a certain amount of drive cycles for the computer to determine that there is no longer an evap leak?

For context, the car has 278,000mi. I purchased it from the second owner who’s had it since 2002. I believe the car sat for about 6 months before I purchased it. This is the only code I’m reading.

 

Hello,

I've had a P0446 code pop up a little while back, it was caused by an EVAP VSV solenoid in the back of the car, near the Charcoal Canister getting jammed with rust. Those can get expensive and they are hard to find used, since it is not the most friendly place for a solenoid, so I came around it by retrofitting a solenoid from under the hood (90910-12196 instead of 90910-12198), which can be found at any junkyard for peanuts, though you will need longer vacuum hoses to connect it, below is the picture of a result.



Hope this helps and best of luck!

 

Thanks for the reply! I just took a look at the canister today and the VSV in particular is in very poor condition. looking around online, I was able to find a few used VSVs in good shape for about $20. I think I’ll go ahead and try to replace it. Quick couple of questions. Did you only get the p0446 code for the problem? Also, do you know the vacuum hose size for the 3 that connect to the solenoid? Mine will definitely need to be replaced.

I was actually able to chip away at the rust (what I assume used to be the metal housing that the solenoid sat in) to the point where it is now gone. I zip-tied the solenoid to keep it in place for now.


(Attached image for reference)

 

I've also had P0440 pop up occasionally, but that turned out to be an old and worn out gas cap.

It appears that a 1999 ES300 had a unique solenoid for the canister, it has 3 outlets to it instead of 2 that came afterwards, Part Number for that solenoid is 90910-12109, you can get one new, but it will take a while, or here you can get a used one for a pretty reasonable price.

As for hoses, Toyota doesn't sell those hoses separately, no thanks to them, so you will have to source those elsewhere. With that, you should be able to find those at any parts store, the inner diameter is 5.5mm, 7/32in also works well. Toyota appears to be making those hoses out of EPDM rubber, which is why they last so long, here is the only place I found that sells EPDM hoses in correct diameter, might as well give them a try.. Regular rubber ones are fine as well, they just won't last as long.

Hope this helps and best of luck!

 

I ended up replacing the VSV with a used, oem one. I did a test with a 9v battery which showed that the original valve was not closing. The replacement valve did close. 350 miles with the new valve and no more p0446 code. Originally, the code would come back about 60 miles after being cleared.

Here’s some symptoms and general stuff I ran into when trying to fix this code:

-Smell of fuel near the rear of the car. (not in cabin)
-Only a p0446 evap code, nothing else.
-Replacement fuel cap did not resolve issue.
-Code would frequently trip when car was stopped at idle.

For anyone in the future looking into this code, I would recommend testing the VSV with a 9v like I mentioned above. You will hear a noticeable click if it’s still functional.

Thanks for all the help! I’ll be sure to update this thread if I run into any more problems related to this code.

 

Perfect, glad that helped, thanks for the update!