PO441, PO442, PO446 New Charcoal Canister and Good VSV

Hello everyone, first post here, long time jeep owner and forum lurker. I recently purchased a cherry 2003 Tacoma Double Cab 3.4/Auto 4wd TRD.

When I bought the truck the check engine light was on and I was given a new-in-box charcoal canister to "fix" the trouble codes. I pulled the bed off (new hardware from frame replacement) and replaced the complete vapor canister unit and reset the CEL. That was on Sunday. I drove around Sunday and Monday. I filled the tank (no top-off) on Monday evening. On my way to work Tuesday morning the CEL came back on for the same 3 codes. That evening I pulled the VSV and tested resistance and (34.7 ohms) and applied 12v to see if it was working properly. Everything checked out okay so I did the same for the other VSV (both located on driver's side fender under the hood). Both VSVs check out okay. I reset the CEL again and it came back on today on my way to work. I can confirm that the gas cap holds pressure by the PSHHH sound when I remove it.

What should I check next to get rid of the CEL? I have read about the rollover valve and check valve. Is it worth getting a smoke test done to check for leaks? All the vacuum lines under the hood and back at the charcoal canister looked okay to me. A few of the squeeze clamps were rusted but I replaced them with screw type clamps.

One other thing that is peculiar about this truck and very well may be related to the EVAP leak trouble code is that after fueling up, the truck will not start without me pushing down the gas pedal. It will crank and crank but no start until I hit the gas.

The inspection/emissions runs out in October so I have some time to diagnose myself.

Sorry for the very long post - I hate reading wordy posts too, but I really need help with this truck! Thanks for any advice. -Luke

 

The tank shouldn't be holding pressure. The EVAP system is supposed to remove the pressure.
I think you MAY have a bad Vapor Pressure sensor.
http://www.parksoffroad.com/tacomamods/maintitems/enginecode/cip0440p.pdf

 

Thank you for such a quick reply! Is there a way to test my current sensor? Actually is the sensor as difficult to remove as it looks? I know it's located down behind the intake on my 2003.

 

check around the top of the gas tank where the sending unit plate bolts on the tank. the edge,rim corrodes and the gasket fails and gas weeps out around the area. take a flashlight and peek in the gap between the front of the bed and rear of cab and look for signs that gas has been leaking. my 2004 did this

 

This is basically what I am dealing with on my '04. Back in December, I replaced the gasket and that worked. No leaking and no codes. I fucked up one of the screws and broke off the head and all attempts to remove it failed but since it worked, I assume 7 out of 8 is fine.

A few months later, it started again. So I cleaned up all surfaces and applied gasket maker to the top and bottom of the gasket. Worked for a few days and got me to pass inspection but P0442 and some other code are back and I am still getting leaking. As odd as it sounds, it looks like it's now leaking out of the screws. The only new spots of wetness I see are around one or two of the screws and nowhere else. I can't figure it out. Of course, I keep wondering if being short one screw matters. But the new wetness doesn't appear to be coming from there.

My next thought is to replace the sending unit plate and all the screws - or at least the 7 I can use. I'd retap the hole but I'm very leery to do any drilling on a fuel tank. Last resort is a new tank, but I will just gasket maker or epoxy the hell out of the whole entire thing before I do that.

 

exactly the same with my 04,i was running the p0442 too after replacing the gasket and using Permatex Permashield gas resistant sealant with it worked for about 2 gas fills then started to weep out again, from then on I never filled the gas tank I put about $20-$25 worth which gave me 3/4 of a tank. I cleaned the mating surfaces as best I could but still leaked. Only cure would be a new tank unless you don't fill the tank completely with gas if u can live with that. You can get a after market tank from Rockauto or AMAZON for less than an OEM one if u go that route, from what im reading they work just as well for less money. I would look into getting a new tank sente3 cause you never really completely fix that problem replacing the gasket on the sending unit flange.

$221 Spectra Premium TO31A Fuel Tank

http://www.amazon.com/Spectra-Premi...=1-3&ymm=2004:toyota:tacoma&keywords=gas+tank

 

Ah so for this issue, seems it's not so easily fixed. I'm hesitant to get a new tank due mostly to price (and I'm sure it's a pain to replace) but if I can get the funds together, I just may do so. It'd be nice to have that leak finally off my mind. And come inspection in 2 years, I don't want to have to fake my way through it again. Not filling the tank crossed my mind, however I still notice the leak at pretty much any point above 1/4.
Thanks for the advice. Much appreciated. And that price is the best I recall seeing for a fuel tank. It's out of stock on RockAuto right now, but that's the same part they offer. I'll probably try again, fruitlessly, to fix it without replacing the tank but I have this unfortunate feeling that's the route I will have to go.

 

i was in exactly the same boat as you, but I totaled my 04 thanksgiving day 2015 so problem solved for me. I tried new gasket with sealant and a good cleaning but it didn't hold up, I think the only permanent solution is a new tank unless you can live with the fuel smell especially during summer. when I was doing the research on mine I seen where people had used that aftermarket spectre tank and also new tank straps spectre brand because of those also rusted with very high success. resealing and new gasket doesn't seem to be the permanent solution to this problem which is very prevalent in GEN1 trucks.

 

Let me get this right - you guys are leaking gas out of the tank. Filling it halfway instead of all the way keeps the leak to a minimum. This won't solve my evap system leak and subsequent check engine light. I need to pass an emissions test in 3 months so the filling half way won't fix the CEL which will prevent a pass on the test

 

lol not exactly the solution you were going for, I'm sure.

Yeah I'm starting to realize that a new way to seal it may be a temporary solution at best. I suppose I could try redoing the gasket maker and then some sort of airtight epoxy around the entire top plate lol Seems worth a try if I'm going to have to buy a new tank otherwise.

Oh sorry to hijack your thread. It was just relevant to my issue, and I figured I'd chime in. As for your specific issue, it does seem somewhat like the vapor pressure sensor, as mentioned. The part is a bit pricey, so I recommend testing it first if you can. I considered replacing my VPS as well because on a few occasions, I noticed an audible pressure release when taking the gas cap off, but it's only been a few times and it could be contributed to other reasons. If yours is consistent, consider that.

As for the CEL and passing inspection, both times I temporarily solved my issue, they codes went away and I'd be able to pass inspection. Not sure what state you're in, but in NJ we only have emissions (really they only test your computer not actual emissions, which is ridiculous) but you're allowed to have 1 emissions system in the vehicle not "ready" for testing (for 2001 and newer; older than that you can have 2 systems). In my case, after I reset my fault codes, I had a lot of trouble getting the evaporative system to ready. It later readied and I had no code or a little, but if I were to have had a code right away, I may have been able to cheat my way through inspection by having that 1 system that would fail me not ready, but I'm not sure. Anyway, my point is that if you can figure out a temporary solution that works for a short amount of time, perhaps you can do it right before inspection and at least get it to pass and then go back to figuring out how to solve the issue. That's what I did with mine. And you can probably go early in your state by a month or two, so if you "solve" it in September, you'll probably be able to bring it through then.

 

So finally an update to my CEL woes. I've been driving my beater jeep while the taco has been parked for winter. Pulled the bed off and found this:

What you're seeing is a rusted flange surrounding what I am guessing is some kind of vapor port for the charcoal canister. After pulling it out(press fit-no turning), I found this:

You can see that the lip of the tank where the seal goes is rusted out and is most likely the culprit causing my EVAP leak. I can easily push the one way vapor valve and rubber gasket back in and it is very loose. I am guessing my best bet it to buy a new tank and gasket set. Replacing the tank shouldn't be too bad with the bed off, just wasn't expecting such a $$$ repair.

Additional pics:

 

Did you ever solve this? I got the P0442 thrown this morning.

 

Replacing the tank got rid of the evap leak codes. It turned out the leak around the rusty hole in the tank was the culprit. These evap leak codes can come from anywhere in the evap system though.

Good luck!

 

Before replacing tank, did your truck smell like gas when it was hot out?

 

@istehwin

I don’t specifically remember smelling gas with the issue, though it’s possible.

 

Subscribing. I was able to pass emissions here in CT by clearing the code with a full tank, driving 100 miles plus, then taking it in. Next fill up, it threw the code of course. But I’m good for two years. I’m guessing my issue is also the seal/corrosion issue.

 

For those following this thread I’ll say that the Spectra replacement tank I bought from Rock Auto developed a leak in the bottom 16 months after originally replacing. It looked like a bad spot weld on the baffle. I replaced with a warrantied Spectra last Fall and it’s been good. Maybe a fluke in production, but something to be aware of.

 

was labor included in the warranty?

 

@Glamisman

Hell no labor wasn’t included. Then again, I bought an aftermarket part and installed it myself.

I consider the warranty on the part cost fair. Their defect could have cost extra labor if I had a shop install it twice, but I assume the shop would provide the part and an overall warranty.

 

from a curiosity point of view... I bought a Spectra tank, first time for me using this product, from my local O' Reillys for the S10 that I am currently tinkering on. Before I paid for it I asked the store manager about a labor warranty IF there is an issue, the bed had to be lifted due to crusty/rusty fittings that are unobtainium on this model/year. I had tried to install it and where the straps that hold it in place wouldnt fit due to the seams needing to be bent up more. I went back to O' Reillys and showed the manager the issue, pretty obvious with a side by side view. The only answer was to take a block of wood and "massage" the new flange bends to match the old with a 5lb sledge. We took turns hitting it until we were both satisfied that it would fit now, he said he would warranty the tank and labor regardless.