Good ol' P0446

[AZBub]

Well, got the OEM Toyota VCV installed. Still throwing the same code. I hope it's not the charcoal canister. I don't want to pay for one, may try cleaning it out with the method I read here somewhere. This emissions stuff sucks! I got till July to figure it out cause that's when I have to take it in for the test.

Replaced the original fuel filter too. Man was that thing nasty!

 

[AZBub]

All the time and money spent replacing all the vacuum lines and VCV's and I am pretty sure I can do a tech writeup based on cheapest to most expensive fix for the P0446 code. Anyway my issue boiled down to this...

 

[1996_Valencia_Owen]

Quick question:

Does the canister (under the hood version) come out easily, or do you have to disconnect any of the tubes/wires?

Also, what's the VSV part number that sits on top of the canister for the under-hood version (96-?).

Much appreciated!

 

[ajonesnv]

Quick question:

Does the canister (under the hood version) come out easily, or do you have to disconnect any of the tubes/wires?

Also, what's the VSV part number that sits on top of the canister for the under-hood version (96-?).

Much appreciated!

It comes out very easily 3 bolts. You do have to pull the lines from the VSV's, but they all come off very easily. I would recommend sealing the canister prior to messing withe the VSV. Also you can check the VSV with a simple 9v battery and two leads.

 

[LV2001BI]

Could use your help

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.

Maritime read all your post on this subject, I just bought a used 2001 I notice that after driving I notice smell of gas fumes & hear a whirling / clicking sound. I don't have any CEl looking at first changing the gas cap since it has some after market that takes Lipitor effort to undo. Anyhow seems what you gone thru is what I'm experiencing

 

[dgjgk]

I haven't had this issue, but I checked my fsm to see what it says.

 

[TXRick]

On my 01, I had the same code. Put on a new gas cap and nothing. Checked a few other evap stuff...nothing. Drove it like that for over a year. The timing belt snapped, so I changed it out. 500 miles later, no CEL...

 

[built4battle]

Hey guys, Jr member here but long time lurker. My truck started getting this code since the end of last year. I haven't noticed if it was happening after a full fill up and I have to admit that I'm a chronic topper at the pumps (ocd). I guess I have to stop. But considering the model year of my runner, my canister should be in the engine bay correct? So topping off shouldn't have any affects to it? My dad use to switch to the truck as his daily, so it didn't get much use during the week. Now that it's mine, it's my DD and I've noticed that after erasing the codes and allowing ample time for the ecu to reset it would come up again.

Started looking at this thread and first of all thanks to everyone that put up so much useful content. First thing I'll do is pull the canister and VSV assembly out. I'm going to test the VSV first with the battery test. If it's good then great, if not, I'll see what condition the canister is in and go from there. I'll try to repair the canister as much as I can if there's any cracks like shown on this thread. If the canister is beyond repair and the VSV is also damaged then I'll order the entire assembly. I'm really hoping that replacing the VSV alone (if needed) and fixing any cracks will solve my issue.

This is where I'm planning to order the canister and VSV assembly if need be: $279 + shipping
VAPOR CANISTER for 1998 Toyota 4Runner|77740-35392

I'll post some pictures to update my post later on to try and help the thread a little bit.

 

[CobraSpdRH]

I have the P0446 code and have now read through this entire thread (very helpful, thanks to everyone who's posted). I noticed my truck has an aftermarket "Stant" gas cap, so I think my first step is going to be replacing that with a factory Toyota gas cap and resetting the ECU. If that doesn't work, I will pull my canister and check it for leaks and proper function of the VSV.

Will post results, but I would say thanks to everyone this thread has more than likely saved people quite a few bucks in mis-diagnosing and going straight to canister replacement.

 

[JBurt]

This is where I'm planning to order the canister and VSV assembly if need be: $279 + shipping
VAPOR CANISTER for 1998 Toyota 4Runner|77740-35392

I'll post some pictures to update my post later on to try and help the thread a little bit.

A good used one would be way cheaper. Maybe give [MENTION=78895]DeathCougar[/MENTION] a PM.

 

[built4battle]

A good used one would be way cheaper. Maybe give [MENTION=78895]DeathCougar[/MENTION] a PM.

Thanks for the heads up, but if I need to replace something I tend to lean towards just buying a new part. Not downing your post, that's just how I am with parts....unfortunately lol. I'm hoping its just the valve because I don't smell any gas from my engine bay at all or see any evidence of cracks on my canister. But I'll be pulling it out anyways.

 

[CobraSpdRH]

Well it turns out the gas cap didn't do the trick for mine. Roughly 30 miles after resetting the ECU the CEL popped back up. I visually inspected the charcoal canister and it appeared to be in good condition, but I am going to remove it this coming weekend and do the 9V battery test to see what's what. Bummer

 

[thor999]

I like to start out w/ the easiest solution first. New gas cap, and no CEL for 1,200 miles now.

 

[ElBrio]

Have this same code for a 2002.
Changed gas cap, code came back.
Replaced canister with good condition (no cracks) one from junk yard and switch next to it.
Code came back 55 miles later.
Does anyone know the part # for the two vacuum switches under the hood? I'm also hearing a noise under the hood.
Thanks.

 

[4racer]

I had P0446 with no other codes. Replaced the charcoal canister with a new unit and problem has been good for 400 miles.

 

[thor999]

I like to start out w/ the easiest solution first. New gas cap, and no CEL for 1,200 miles now.

Why did I post this? OK code is back lol

 

[NBBAZ]

Here's a new wrinkle in the P0446 issue, I think. My cel for this code came on so I did what many others have done first, replace the gas cap and clear code with scangauge. I don't overfill the tank anymore and now the only time my T4R throws the code is when I change elevation drastically like this weekend when I drove from Phoenix to Flagstaff, approximately 5000 feet higher. Sure enough, P0446 pops up! Drives fine.

 

[thor999]

Here's a new wrinkle in the P0446 issue, I think. My cel for this code came on so I did what many others have done first, replace the gas cap and clear code with scangauge. I don't overfill the tank anymore and now the only time my T4R throws the code is when I change elevation drastically like this weekend when I drove from Phoenix to Flagstaff, approximately 5000 feet higher. Sure enough, P0446 pops up! Drives fine.

That is mostly when mine comes on too, and drives fine.

 

[1933beer]

Long thread two things I wish 1 separate discussion of the 2 models. Have someone create how too or video for checking replacing the pads related to this issue.
I have e had the issue for a few months. I have reset my system once and lights came back. I have ordered a new cap it's cheap but doubt it will fix any thing. My 02 has 130k. I noticed post78 the guy replaces just the sensor on the canister. is this being done by others with success? I would do this first if it works.

 

[1933beer]

OK I put the new cap on today later I came out got in hooked up the tool to reset the codes started it up and the check engine light is gone I looked for codes and none to report. ? So it appears it cleared on its own. I am very skeptical that a new cap is the fix. My old cap looks fine. The truck has not cleared on it own. If it's fixed I just saved $300 dollars.☺☺☺☺☺