P0446 troubles

[troy_279]

So after throwing this code almost weekly (along with 0440 and 0442) with my 02 limited I'm getting tired of resetting the CEL. From the extensive reading that I've done I think I'm at the point of replacing the VSV at the charcoal canister. I've checked all the lines and everything looks good so I guess this is the cheapest part to replace first. My question is has anyone ever used anything other than a genuine toyota part? I have found that my local Canadian Tire (yes, here in Canada) has the part from a company called Dorman. I was just wondering if anyone has tried this part.
Thanks

 

[troy_279]

Nobody?

 

[LittleCaesar]

Troy,

I have never used anything Dorman on my 4runner; it seems to really like OEM parts only, with a few exceptions. I have used Dorman on American cars and been OK with them.

Read this first:
http://www.toyota-4runner.org/3rd-gen-t4rs/53593-good-ol-p0446.html

Car-Part.com--Used Auto Parts Market - to see if a junk yard near you has one.

 

[troy_279]

Well I decided I would just call my local dealer and order the VSV. For some reason they gave me an item number of 90910-12245 and I thought I needed 90910-12264 and they gave me a price of $100. I didn't order yet, hoping an expert here would chime in.
Thanks

 

[masphx]

I had and still have PO446. Took it to a mechanic and did smoke test (nothing). He tested the two valves on top of charcoal canister (98 4R) and both had failed. He replaced both for $300 and I still have the PO446. This was a year ago and I still have the code every now and then. I just turn it off as I still get good gas mileage (~20 mpg). So far my PO446 has cost me $360 USD. It's probably the charcoal canister in my case.

 

[troy_279]

Well I'll pick up the Dorman VSV tomorrow and put it in to see what happens. I got the whole charcoal assembly off tonight so i'm ready to bolt the new one on and re-assemble. I must say what a PITA. It took me over an hour to get the assembly off but on a good note I only broke one bolt! I can't even imagine changing the VSV without taking the whole assembly off the truck.

 

[troy_279]

Well new VSV is in. Heres to hoping all goes well!

 

[troy_279]

Well after a day the 0440 and 0446 are back. I guess a new gas cap is in order first and we'll go from there.
Thanks

 

[LittleCaesar]

Troy,

Sorry to hear such. I'd still try and find a used one, even though a new cap won't hurt your wallet.

 

[jtfitz90]

I've got this same issue. Just haven't gotten around to taking a look at it yet. Have you noticed a decrease in your gas mileage since you've had this code?

Also, when I go to check the VSV and/or the charcoal canister, do I need to remove the gas tank? Thanks.

 

[Maritimer]

Read this first:
http://www.toyota-4runner.org/3rd-gen-t4rs/53593-good-ol-p0446.html

Take LittleCaesar's advice, first.

 

[troy_279]

That is an excellent thread and I've read it and it seems a hundred more that google has found. After replacing the VSV at the charcoal canister I'm still throwing codes. It is now 0440, 0441 and 0446. I just went with what seemed to be the common fix with the VSV but I guess I'll get out the multimeter tomorrow and test the switches under the hood and go from there.

 

[troy_279]

Also, I've had no decrease in fuel milage. I consistently get 300 miles to a tank.

 

[troy_279]

Well I had a couple minutes today so I got a chance to test all 3 VSV's. All 3 are with specs for ohms according to the service manual but i wasn't able to connect 12V to see if they actually created vacuum. I inspected all line from the front to back and all look good. I guess its time to find a charcoal cannister.

 

[Maritimer]

What part of Canada are you from? If you live in a salty area, the condition of your filler pipe might be worth a check. My pipe was a mess, so replacing it was a good idea anyway. I still had the code, but a new gas cap fixed it. Now, the PO had the code and tried a gas cap first. I guess it is possible that his OEM cap was shot and the new one just didn't work, but I think that it was a combination of the pipe going and then the replacement cap sucking. Anyway, I don't have the codes anymore. One of my valves was replaced, but it did squat (or it could have been a third piece to the puzzle. I was reluctant to do the canister because of price.

 

[rmartin929]

Solution for P0446

Solve your P0446 easily: 1999 Toyota 4cyl 4runner EVAP Canister fix P0446 - YouTube

Had the P0446 for years. I read forums, chased down vacuum leaks, and tested canister valves - I did conclude it was the canister. But, I got into the habit of clearing the OBD and driving just the "right" amount of miles to pass emissions before the check light returned. Today, emissions test due, and I had tracked down a 4runner at a junkyard to go pull/buy the canister. Thought I would review a vid on replacement 1st and came across this as I was getting ready to leave. Did the spray test and bingo! I had leaks on both front corners! I really love fixing stuff vs. trashing it. JB plastic weld, passed emissions, exhaust literally smells better; and I'm confidant this was the cause of P0446 and a great solution.