P0440,P0441,P0446 trouble codes

got a 02 Taco 2.4L thats throwing these codes. I know its some sort of problem with the evap system. Any idea what the cause could be?

 

This is for a first gen tacomas you should post in the 2nd gen tacoma forum.

 

he's got an 02 dude. thats a 1st gen. this is probly going to sound stupid, but have you checked to make sure your gas cap is tight? sometimes that can throw an evap code. also check vac. lines around the engine compartment just to double check.

 

EVAP codes. I would start with checking fpr any vacuum leaks. Oh yeah not to insult you but make sure the fuel tank cap is not loose.

 

My b. Just looking at his sig.

 

yeah sorry the sig through you off lol i did check the gas cap. it was tight but i took it off and put it back on again. this truck threw these codes a while ago. when i replaced the battery a few weeks ago it obviously reset the CEL but it stayed off till yesterday. i must have put a few hundred miles on it before the CEL came back on. Ill cleared the code back out yesterday so i will be checking for vaccuum leaks today and keep you updated. thanks!

 

This is the only time I promote the method I will propose. Sea foam through the brake booster vacuum line. Look for white smoke around the intake vacuums and exhaust leaks. Otherwise I would start with oxygen sensors since they are the most common culprits.

 

Yeah i dont think its a vaccuum leak just cause it idles so smooth. and if it was the O2 sensor, wouldnt it throw a code for the O2 and not the evap? what about the VSV? iv hear these are a common problem on these trucks

 

evap codes are such a pain in the ass. i had an o2 and evap codes, replaced b1s2, but the light came back on. theres gotta be a dtc flow chart somewhere on here right?

 

PM me your e-mail address. I have a PDF file that shows how to diagnose the VSV. I was gonna put it up on mega upload and PM you the download link but Megaupload is down.

 

tagged. Just got the same codes on my 2002 2.4

P0440
P0441
P0446

Any update on this?

 

I have the same 440 code. had 440 + 446 before resetting with efi fuse. tarded. best answer. buy or make an electric car

lets hope we can win this latest electric vehicle battle so we never have to deal with this kind of nonsense again. basically no more of this contrived vehicle "service" economy. another of grandpa's failed legacy systems; it's all the last 100 years of purposely complicating/manipulating at peoples expense, for their precious profits and economy.

 

I have the same fault codes for my 02 Tacoma:
P0440
P0441
P0446

I am going to replace the Vacuum Switching Valve located on the Charcoal Canister, I watched these videos (I was going to replace the whole canister until I watched these):

Part 1: https://www.youtube.com/watch?v=GAzOOWfje9o

Part 2: https://www.youtube.com/watch?v=PDuiopc2ic4&index=3&list=PLX_Dy3QSITgg2w3Yx7kpwEuMpk-WVuHeN&t=555s

 

Any updates on this? I've had the codes for more than a year now. Did a smoke test, found smoke coming from the filler neck area, so I replaced the filler neck and the small fuel filler hose. I'm getting these codes again now, so I'm not sure if this is the right solution because the video is for a Sequoia

 

for the weekend repair warrior these have a tendancy to be impossible to locate and fix as the leaks are so small. If you have a decent scan tool you can see the exact conditions that were present when the CEL was tripped in Freeze Frame Data.

Evaporation codes are what is called 2 trip codes. for the evap monitor(s) to run and test, the fuel tank HAS to be between 1/4 and 3/4 full, the air temp sensor and water temp sensor have to be within 10 degrees (apx) of each other and the vehicle HAS to have sat at least 8 hours and this has to happen twice.

There is a recent post where guy had an evap code and he took it to the dealer and they recommended a fuel tank, he authorized it and a few days after the same code popped. Now, was this a multi problem issue, probably. I do not think the system was smoke tested after the repair to verify if it was fixed.

A professional smoke machine not only creates smoke and pushes it through the system it also monitores pressure in a very small amount. The parameters for small leaks are .030 and large leaks .060, IIRC. You might not see smoke from a hole that small but you will see it isnt holding pressue.

If your state has smog tests the testing facility has a fuel cap tester as part of the smog machine... you might find a nice guy and he will test your cap for free or just replace it with a new one. Cheapest and easiest to do.

 

I wish I had an update, mine is still throwing the same codes, light has been on for about 3 years now. I learned how to cheat the system for SMOG checks if anyone is interested in that information let me know.

I have yet to replace anything other than the Fuel Cap (I'm a cheap ass and I'm still hopeful for a guaranteed solution)

Those videos I posted are not completely accurate the charcoal canister is different and they seem to force you to replace the whole thing, the real problem is that there are no tutorials specifically about my year/model.

This video was my next find, it would just be a lot less complicated with a lift (you can skip to around 14:00 for removal of the broken check valve assembly and gasket that was causing his leak). Video is for a Toyota 4runner, but its most of the same parts since it's an 02:

https://www.youtube.com/watch?v=D-HPp2-_PFM

His receipt (from the video) for reference:


Please update here if you end up changing any of these parts out, I will do the same.

 

Seeing as you've had the same codes for 3 years already, I think these aren't important at all and more or less just a waste of money to get rid of a check engine light. My truck runs very fine and gets me about 20mpg, so I'll probably never try fixing it again . Maybe one of these days when I'm flush with a bit of extra cash, I'll take it to a professional/reputable shop to have it fixed once and for all. When that day comes, I'll make sure to update here.

 

Sorry to revive an old thread, but I’m throwing the same codes. I replaced the gas cap to start, CEL came back. Replaced the entire charcoal canister myself with oem part after Toyota dealership ran diagnostics and smoke test and said the canister was leaking, codes are back. Toyota dealership recommends vsv and purge solenoid to be replaced next to fix the issue.

it’s been going on for almost a year, but I can’t pass inspection with the CEL on. Any help?

 

Get a 9V battery and some test leads and check the 2 VSVs for the evap under the hood. You can google it but basically take the vsv's out and put a lead on each pin and see if you can hear it click on. you cant miss the click. if the VSVs are alive, they'll click. once you know that they are alive, follow the FSM and blow into them with and without the leads connected. this will tell you if they need to be replaced. you can also take another step and get an Ohm meter or a multimeter and see A) if they have continuity, and B) if they read the correct ohms (~30-35 ohms at room temperature). if they are good, i guess move onto the vsv on the canister, even if its a new piece. eliminate all those as possibilities. if those are all good, and you checked all your hoses and they are good, then i think you need to move onto checking all your gaskets on the fuel tank. this includes the filler neck and roll over valve. check all of this yourself before letting the dealer have you start throwing more parts at it. let us know what you find.

for the Canister VSV (part number 90910-12250):


For the VSVs under the hood (part #

$55 25860-75230 Vapor Canister Purge Solenoid

25860-75230) :


For the other VSV under the hood (part #90910-12245):

 

these are the most difficult codes to troubleshoot due to the time involved. One good thing that is happening is that the evap monitors are running and that is half the battle. I have attached the vapor pressure sensor diagnostic... this si the device that senses the rise and fall of vapor pressure in the fuel tank which is what is used to set the CEL.
I do not know if the state you live in allows for any of the monitors to be incomplete AND you still be able to pass smog. Evap monitors are notorious for their difficulty to run due to the unique conditions required to have them start. If your state allows for 1 monitor to be incomplete and still run the smog test, I would keep the evap monitor incomplete by keeping the fuel tank full all the time.