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Toyota Code P0446

2001 Camry 4 cylinder. Check engine light came on yesterday. Advance Auto pulled out the code P0446 for the evap. emissions system vent circuit.

Any information on how to fix this would be greatly appreciated.

The car has no symptoms other than this and is current on all maintenance, but obviously it is a 10-year old car and so it goes.

Thank you, CSA.

Mleich, I’d Try The Procrastination Strategy, First.

Since it only came on yesterday, I’d wait a day or two or three before doing anything. Sometimes these codes appear and then self-correct (like Norm’s underwear on the old “Cheers” TV show.)

Then if that code and CEL persist you should proceed with troubleshooting.


New (To Me) Information For 2001 Only Camry And Solara Vehicles.

Read a copy of Toyota TSB (technical service bulletin) #EG010-01 (engine group). The TSBs are for Toyota technicians and not written for DIYers.

You’ll need to see if you’ve got the old part number ECM (Engine Control Module) or the new one. I guess you can start by checking your VIN as their was a production (assembly line) change-over. Try checking the ECM part number.

If it’s your ECM then working on the EVAP system isn’t going to fix it.
Good Luck,

Thank you so much for the additional info. I will print out a copy and check my VIN, but am currently using the “procrastination strategy”. I did make sure all related wiring harnesses and hoses were securely fastened. Then I removed the positive battery harness for about a minute to clear out the computer’s memory. No more light!

If you typically “top off” the gas tank, that is continue to add gas after the nozzle shuts off the first time, you will eventually get this code. The procrastination strategy works in this case, as long as you stop on the first click in the future.

i hav a 2000 camry i had this problem i replaced the VSV that is by the gas tank and this solved the problem i noticed that the idle was a little low when i had this problem the vsv cost about $50 at the dealer

Amoher problem spot on Toyotas is the gas filler tube. I’ve seen many of these rust out with small pinholes. I’d test the gas cap first, then make sure it’s on tight. Drive for a week or so to see if the light comes back.

On my 2002 Sienna, several years ago, I had intermittent 0442 and 0446. Sometimes it would go months without a failure. Then, it would fail a lot.

I did not take it to a mechanic, because the odds of it failing while the $85/hour clock is running are very slim.

I replaced the cap, more than once. I also left the code reader on it, so I could see when it failed. And, I Googled to the point of nausea.

Finally, on the old Sienna Club a man said he had the exact thing, and owned two Sienna’s. He swapped parts until he found the fix. it was the canister assembly. He said it looks like it had some low pressure, self-actuating valves, and he theorized one might have been sticky.

I took my Sienna to the dealer and told them I was taking responsibility for the troubleshooting, since I did it for 31 years. Problem has not come back on the passing years.

So, you need to find out if it is truly intermittent. Note when it failed, and if it comes back again, note that as well, until you get a handle on it. That is, learn how intermittent it is, or if it was a one time thing, as others have said is possible.