Good ol' P0446

[Jungoes]

I got this code today (P0446) , so long story short, if i don't need to pass emissions for my area should i even bother about it?

I got P0110 and P0100 both which cleared after I cleaned the MAF sensor put the P0446 is still showing up after clearing the codes, other than that the truck runs fine, no issues.

 

[illone21]

I'm having a horrible nightmare because of this (p0446) code. I've failed vehicle inspection (NJ) and even though I've been able to have the code cleared (code reader/reset, disconnect neg. battery) it fails reinspection because the ODB system is not ready yet. So, I drive for 100+ miles (as recommended) and low and behold the light is back on again.

I've had this vehicle in the shop a few times last year to have the problem fixed and it always comes back. I'm trying to avoid taking it to the Toyota dealer but, I'm running out of ideas.

 

[Maritimer]

Nelson will kill me for saying that I still haven't got a new filler pipe yet, but here goes.

I get the 0440 series quite often. I'm getting a new filler pipe that should be done anyway and will probably fix my problem. I deal with the codes with a cheap scanner I got for $60 and it's as easy as anything to erase it every week or so when it happens and not have to do the battery unhook.

A LC guy I know was having problems and he moved the solenoid from near the canister because the heat was too much there or something. Anyway, he never had the lights again. Now, the interesting thing is that my light usually comes on the morning after a fill up, and I had my spare out for a week while I was grinding and painting back there and had it inside the truck. Anyway, no code for a week with good ventilation. Could be luck or could be something else.

 

[Tinabell85]

I just threw the P0446 code (alone). Dropped my spare today just to see if there were any cracks in the vapor canister, looked fine. I went on Car-Part.com to see if I can find a junked 4Runner to donate a part to my baby. Hopefully that's the fix.

I haven't noticed anyone else mention this before but before I threw the code I had difficulty filling my gas tank. I'm assuming a line is clogged and that cause me to overfill which caused the P0446 code. Just wanted to see if anyone had an issue like this and THEN had a code?

 

[Maritimer]

I threw codes all summer, but yesterday when I had my truck in the shop they did a test with their new computer (on the house, as they wanted to play with it some), and it ran through all the valves, the canister, the fuel tank, and did pressure and vacuum tests in each area, and the conclusion was nothing was wrong. Maybe, I pray, a new gas tank cover will do the trick. My current theory--the old owner replaced the gas tank cover first (with a crappy one), but the problem was really the filler pipe. I replaced the filler pipe, but still have a sub-standard gas tank cap. I'm going to get an OEM one if the code appears this summer. Hopefully that computer test saved me the cost of a canister and some valves and a smoke test.

 

[Maritimer]

I'm patiently biding my time hoping the CEL doesn't show up. I'll know for sure by July, I guess.

The filler pipe went on last summer, and I mean, for its rust, it was a no contest replacement with or without codes. I put an OEM gas tank cap on last month, and we've already had our fair share of warm weather so far this year--which was the trigger for my codes--never got codes in winter.

Don't want to jinx myself so I am knocking on wood, but here's hoping.

 

[troy_279]

ever get anymore codes?

 

[Drcoffee]

This is not unique to 4runners. My Acura MDX had this code Evap and the dealer told me it was the gas cap or possibly something in the canister, blah blah blah. So I told him to replace the fuel cap but he was taking it back if it didn't work. The cap he wanted to replace was new. Long story short, I found out that topping off the gas tank is what causes the problem. Because the gas level is all the way up the filler tube, the gas gets into the line to the Evap and causes a malfunction. Since then, I stop filling the tank when the handle clicks off and dont add any more. After 2 or 3 tankfulls the line cleared up and the CEL went off and didn't come back. I'm not saying its the only solution but it made sense to me and worked. We all want to put as much gas in the tank as possible, but it's possibly the cause for the Evap system error.

This was the advise I got from the service writer at Acura after I told him I didn't plan to pay $$$ just to turn off a light that had no effect on the drivability of the truck.

 

[sonoranrunner]

Any chance that you leave your car idling while you fuel up? This same code happened to me... Lil 3yr old boy, and had to leave AC on while fueling.... And Threw same code. Local junk yard solved the problem with a used charcoal canister.. 50 bucks

 

[Maritimer]

ever get anymore codes?

Nope, and being July 12th, I'd say I'm clean and clear.

I'm glad I didn't put a new charcoal canister in, as Toyota recommended i9n 2010, because that would have been a waste. All they did was read the code and make a half-assed guess. I hate wasting money on lame service, and I'm glad I have this site and two more years of knowledge on cars (I knew squat until I came back from Korea at 31 and bought my first vehicle).

My shop ran a decent diagnostic test in the winter that pressurized all the valves, the canister, and the gas tank, and determined that everything was fine. I figured it must have been the non-OEM gas cap that was the final problem, so I replaced it cheap, and things were fine.

 

[rpearlberg]

4Runner was in the shop a few weeks ago for a service and the CEL light was on. They replaced some sensors, pumps, etc...a few days later the light came back on. It's P0446. They told me it's a vacuum valve (or something like that)...part is $86 plus about 2 hours of labor. They said they need to remove the charcoal canister to get to it...

 

[masphx]

4Runner was in the shop a few weeks ago for a service and the CEL light was on. They replaced some sensors, pumps, etc...a few days later the light came back on. It's P0446. They told me it's a vacuum valve (or something like that)...part is $86 plus about 2 hours of labor. They said they need to remove the charcoal canister to get to it...

What year is your 4R?

 

[rpearlberg]

2001 2WD 150K miles

 

[masphx]

OK, they need to access the canister from underneath your truck. It is not in the engine compartment but near the gas tank. I'm sure you could do the job yourself if you are up to it.

 

[rpearlberg]

Ok thanks, so it sounds about right. Hopefully this takes care of the issue...then it's on to new tires!

 

[Tilt]

This has to be the biggest BS pain in the butt thing on 4Runners. We have this dreaded code on our '02, and I feel so powerless to figure it out. Anything to do with the dealership will cost hundreds of dollars - just to get it fully diagnosed. Not to mention I was just quoted like $740 just for the canister assembly. Living here in Canada, I may as well be on the moon when it comes to 4Runner stuff. The junkyards have VERY few 4Runners - and the ones that have them, know exactly what they have. So even used parts are insane. Arrrrgh!!!!

 

[28.]

I'm glad I read this thread and saw about overfilling gas tank...I do it all the time trying to get an even dollar amount in there. I gotta stop my little OCD games, LOL. When I turn my truck off I hear what I always thought was the canister hum a little and make some weird noises like it's releasing pressure. Is this a bad sign or just normal like I believe it is?

I have that same OCD problem lol.. drives my wife nuts haha..

 

[uscfroadie]

My P0446 Fix - $42

Hello All,

Long time lurker, first time poster.

I had the P0446 code pop up on my 2001 4 Runner Sr5 4X4 and came here to read up on the cause/fix action. I reset the code twice and had it re-appear in a short amount of time (less than 50 miles of driving), so I knew I had a problem, not a fluke. Not being one to change parts for the sake of changing, I did more research as there was no one simple cause.

I found this video - YouTube Toyota P0446 Video - that centers around the same problem, only on a Camry. The basic principle is the same, so I used this as a basis for my troubleshooting.

I removed the canister, which is a bit of a pain, at least on my 4Runner. Spare tire, 4 bolts, one electrical connector, and 6 hoses, if I remember correctly, had to be removed, and some of the connections are in really tight spaces. Still, its not difficult, just harder than it should be.

With the canister out, I performed the vacuum test specified in the video (linked above). Mine would not hold vacuum, hinting that the VCV was stuck in the open position. According to the video I needed to replace the entire canister, but being that I'm not one to top off my tank, I didn't see how the canister was bad, but I knew the valve was. Versus ordering a new canister online for $370, I opted to look for just the replacement valve, and lucky I found that it is available separately, just not from Toyota.

My local Autozone showed one for $42 and could get it within 3 hours (would be delivered from a nearby store). My dad and I ran up and looked at a print out of the piece just to be sure given that Autozone was only about two miles from my Dad's house. Yep, same part, so I ordered it. (Inserted a picture of the part below).

Three hours later the delivery truck arrived, as promised, and I was home installing the piece a few minutes later. Once again I performed the test, and it all checked out as it should - vacuum when closed; apply voltage and vacuum purges, so I (with the help of my Dad) re-installed the canister.

I reset the code and since then have put nearly 1,000 miles on the 4Runner without having the code re-appear. I even plugged in my scanner just to be sure. Yep, still no code(s), so I consider this problem fixed.

I hope this information helps someone else on this forum should they get this code on their 4 Runner.

Cheers!
Merle

 

[ajonesnv]

So, I will bring up an old thread.

I too have the P0446 code. Im going to start with the last posts suggestion and hope for the best. However I did notice that the fuel pump was getting louder and louder as of late. Do any of you guys think that could be related. It was about a month the code was tripped since the fuel pump got loud.

 

[ajonesnv]

Alright, so I pulled the VSV solenoid out and tested it with a 9v battery. There was no response. I luckily I found one on Ebay that was originally bought for, what turned out as a misdiagnosis, which means I got a new one for used price. Once I got it I tested it with the same 9v. It responded accordingly. The OEM part number is 25860-75160. Fortunately, my canister is under the hood, so it will be very simple to replace.

I did however, reset the code and it has not come back on yet. I kinda feel like I should wait for it to come back one before I do the R/R to have assurance that this was the issue in fact.