My check engine light came on yesterday. I stopped by Auto Zone this morning and code p0446 came up... this is EVAPORATIVE EMMISSIONS SYSTEM VENT CONTROL CIRCIUT.

Has anyone had this on their car (1999 RX 300)? Can anyone give me an estimate of cost for this?

Thanks.

 

Have you tried removing the gas cap, check the seal while you have it off, and then re-install it and make sure it's seated tight? That is often the reason for that code. Also, make sure you NEVER top the tank off like we used to. TOPPING off floods the emisions canister and causes the problem also.

 

Code58,
Thank you. I have tried the gas cap, but I did not check the seal. The last time I filled up I do top it off. Maybe that was the problem. Will the check engine light go off on its own or does it need to be reset?

I will look for that again today. Thanks for the reply.

 

I wish I could answer that question Dietz, but I can't. From what I remember, I believe it may contaminate the "charcoal" in the emissions canister (if that's what they still use) and MAY not clear, which means may need to be replaced. Don't panic though, I'd give it some time to clear itself, if it doesn't, try having it cleared or removing the ground cable for a few minutes and see if that clears it. I wouldn't lose any sleep unless it CANNOT be cleared, then deal with it. I have topped off a few times over the years without any problem, but never "top to the last drop" like you used to be able to. Normally I don't risk it and call it a day when the pump shuts off, because I know that won't flood the canister like "clickity clickity click" will.

 

We have Fuel reservoir (tank), fuel delivery and return path for the gas vapors back into the fuel tank [the back path has a filter (charcoal)]. This loop is monitored for leak and has the mechanism to measure loss of fuel due to consumption.

There is a liquid path and then there is the vapor path in the loop. Due to gravity the liquid path is below and the vapor path is high up. The highest point for the vapor is right below the filler neck.

As you fill gas, and if you overfill it (get is to the cap level) the liquid gas enters the vapor path and makes it way to the charcoal filter.

Repair cost:
The major cost is in finding what is wrong. A leak can spring any where, loose clamp, rotted hose, broken fitting and knocked off hoses etc. Special equipment like the smoke machine [non-combustable smoke] is used to introduce smoke in the system to trace. It can be a quick find or may take hours.
The failing part can be a disconnected hose ($0) or could be worth $$$ if a nipple is broken.

In RX it is mostly the gas cap [you need to trun it for about 3 clicks beyond the stop]. State/County inspection stations can test your gas cap to see if it needs replacement.

Salim

 

When I got this code P0446, I had to replace the charcoal canister assembly located under the rear of the vehicle. After that, no more Check Engine Light!
-I did try a new Toyota gas cap first. (Sold by the Lexus dealer)
That wasn't it.

Barryst

 

I had this looked at by Lexus last Thursday. They told me I needed an entire cannister that is was not just a valve. Part only was $670. They charged me $175 in labor. Some how I feel like I have been taken for a ride. I talked to two shops and they said the most they have heard was $310 for a cannister.

I want to write to Lexus president. Does anyone have an address for the corporate head quarters. This is unreal.

thank you

 

Everyone knows that the dealer is going to charge way more than necessary. So, if you were going to compare prices why even go there? You went to the Lexus dealer, and you should have expected a hefty number that isn't anywhere close to what it would really cost.... Lexus won't give a damn, LoL.

 

I'm going thru this ordeal as well, i have a thread about my tranny that I'm discussing it.... I took it to Toyota today and they quoted me $956 for the canister assembly, telling me you can't just get the valve.... I had JAB on this forum direct me toward a part number that turns out to be a corolla canister Vsv....I've had the dealer order this, and they are going to attempt to install it tomorrow am....cost of this Vsv was $153.00.......
The parts girls and myself went thru a few cars, some show a Vsv separate from the canister as a part number.....others do not... It gets weirder because I gave her a corolla part number...but when she goes to look at the corolla diagrams,,,it doesn't show that part,,,, when I google the part number it does come up on a Lexus part website...but doesn't list what cars it works on....



Wish me luck....I'll report my findings...

 

Yes, the p/n I provided is associated with a Toyota Corolla, and it was from a Toyota dealer that I bought mine, for $115. But, my Lexus dealer also recognized the p/n but wanted $175 for it. Keep in mind that this is only for the 1999-2000; cannister assembly (charcoal, VSV, and some miscellaneous devices) changed in model year 2001.

 

I think a lot of things changed after 2000, from what I can figure the first two years were SUVs literally made from all sorts of parts from other Toyota models....from corollas,camry to sienna and highlanders...
I'll report tomorrow am with my totals and the dealers reaction etc.. Since they are installing as well..

 

Confirmed that part installed without issue and cel not back with 300km since. I'll report back if it comes back. total cat was $311. Taxes in.

Cheers to JAB

 

My 2010 RX350 check engine light came on. I had the gas cap replaced but after a few days the check engine light is on again. My mechanic tells me that the problem is somewhere else in the fuel tank system. Took the car to the dealer, after a few days they said they fixed the problem, but 5 days later the light is back on again and I have not touched the gas cap for a couple of weeks.
I contacted the dealer and they want me to bring the car in again. If they do not fix this problem soon I am told that my car will fail the California Smog Check in Dec 2013. I am also concerned that my warranty will expire. Any suggestions ? JohnR

 

If you took your vehicle to dealer, you are in good hands. Take it back and ask them that they perform the State mandated inspection as well. Enjoy the benefit of one stop shopping.

Salim

 

When you get any of these codes for Evap system I always suspect one of those tiny vacuum lines that run between the engine, gas tank, and evap canister.