1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

2003 with a PO456 Engine Light Code

Discussion in '1st Gen. Tacomas (1995-2004)' started by ugmold, Aug 8, 2012.

  1. Nov 12, 2012 at 6:57 AM
    #41
    Toyota-Dually

    Toyota-Dually Member

    Joined:
    Dec 28, 2009
    Member:
    #28321
    Messages:
    18
    Gender:
    Male
    First Name:
    David
    Holden Massachusetts
    Vehicle:
    TRD 4x4
    If you don't read the other posts???

    Post by UGMOLD:
    You looked at the top of the tank for signs of rust.

    I posted the photos to show that looking at the top of the tank for rust holes will not show you where the rust is and that is.. under the seals.

    My old tank top looks just as clean and rust free as the new one.
     
  2. Nov 13, 2012 at 6:23 AM
    #42
    ugmold

    ugmold [OP] Well-Known Member

    Joined:
    Jan 26, 2010
    Member:
    #30066
    Messages:
    122
    Gender:
    Male
    The local mechanic did and, and did a pressure and smoke test on it, thanks for the pics and replies.
     
  3. Nov 26, 2012 at 9:50 AM
    #43
    ugmold

    ugmold [OP] Well-Known Member

    Joined:
    Jan 26, 2010
    Member:
    #30066
    Messages:
    122
    Gender:
    Male
    Well nearly a month has gone by and the engine light has not come back on. Since the temperature has dropped below 55 the smell has subsided as well. hmmm.
     
  4. Nov 26, 2012 at 10:07 AM
    #44
    85GT 79FJ40

    85GT 79FJ40 Well-Known Member

    Joined:
    Dec 16, 2010
    Member:
    #47768
    Messages:
    1,113
    Gender:
    Male
    First Name:
    Ken
    New Hampshire
    Vehicle:
    19 TRD Sport DCSB 6M - 2017 Honda Africa Twin
    My dad's truck has the same code. Randomly comes and goes. Sometimes it comes on 2-3 days after I reset it sometimes it stays off for months. His is an 02 or 03 can't remember which. No gas smell on his though. But other than a leak in a hose that smell would make me think either the filler neck or canister would be bad. Honestly on his I haven't even done anything but read the codes. But I was chasing a similar issue in an 02 Rav4 recently that was getting P0440,P0441, and P0456. Filler tube was completely rotted out. Replaced it. Codes still there. Pulled off all the underbody cladding and checked all the hoses and found no leaks, so I took another stab at it and replaced the purge valve. Codes are still there. The canister on that one is $265 and it's registered in Vermont where they don't care if the light's on for inspection apparently. So I don't think it's getting fixed.
     
  5. Dec 16, 2013 at 10:58 AM
    #45
    ugmold

    ugmold [OP] Well-Known Member

    Joined:
    Jan 26, 2010
    Member:
    #30066
    Messages:
    122
    Gender:
    Male
    Just an update here, over a year later and the light stays on, I smell gas and there seems to be no cure.
    -ug
     
  6. Jun 28, 2014 at 6:00 AM
    #46
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    old thread, but my 2003 double cab is starting to throw a po456. Replaced with oem parts purge solenoid, (last year fix for a check engine code I forgot,) and recently a new oem gas cap. I'm guessing the cap won't fix this problem. Parts guy at Toyota with the same model had a tank leak at the sending unit seal. So I guess a new tank probably will be the fix. A couple of questions: remove bed? or drop the tank from below. Is there an access panel to get at the electrical connections from the back set area? oem or aftermarket tank? Where can I source an aftermarket tank? Ebay has one, but no one else seems to offer one that I can find.
     
    This site contains affiliate links for which the site may be compensated.
    #46
  7. Jun 30, 2014 at 10:51 AM
    #47
    ugmold

    ugmold [OP] Well-Known Member

    Joined:
    Jan 26, 2010
    Member:
    #30066
    Messages:
    122
    Gender:
    Male
    Hi rosst,
    I started the thread and still have the problem. My local mechanic took down my tank and filler neck and pressurized/smoke tested and couldn't find anything. It has been very frustrating given the fact everything else on the truck is decent at 140,000 miles. My guess is that is the ethanol in the gas. Here in Mass, we have 10% added ethanol. My truck was not designed to use this, as are my old Motorcycles and lawnmowers etc. I think the pressure of the ethanol in the system is what is causing the leak, I never smell it on a cold start, only after it has run a bit.

    I do recall one evening years ago, filling up and when I open the gas cap, there was a pressure build up, but I didn't think too much about it. Might be related. I just got laid off so I'm going to have come up with something, a new tank/filler neck might work for awhile. Problem started at 120,000, replaced the gas cap, charcoal canister, and did the pressure test. It is yearly inspection that I worry about, I was able to pass this year by blanking the computer and passing emissions, but the test also revealed the Catalytic converter was in need of replacement too.
    -ugmold
     
  8. Jul 1, 2014 at 10:55 AM
    #48
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    Thanks ugmold, I seem to have temporaily solved it by installing a new gas cap. My 2003 dbl cab has only 50k miles on it, but sensor faults are starting to wear on me. I do my own work, but so far in the last 18 months or so I've changed the o2, the AF the solenoid purge valve for various CEL codes. I may pull the bed off sometime later this summer and really give the whole evap system a good inspection. I live next to Mass in NH, so I know what you mean about the ethanol. My local Toyota parts guy has the same truck and had slight seepage on the top of the tank. I guess where the sending unit goes, the mating surface for the top plate gets corroded. Might be hard to see in a visual exam. I was going to see if there's a gas safe sealer that might seal it without replacing the tank.
     
  9. Jul 1, 2014 at 6:18 PM
    #49
    Toyota-Dually

    Toyota-Dually Member

    Joined:
    Dec 28, 2009
    Member:
    #28321
    Messages:
    18
    Gender:
    Male
    First Name:
    David
    Holden Massachusetts
    Vehicle:
    TRD 4x4
    I had the same problem. Smoke test couldn't find it so I just decieded to pull down the tank and evap parts and eye ball everything where I could see things clearly and start replacing anything that looked worn, cracked or bent. Turned out that when I removed the rubber gaskets on 2 big openings into the tank I had finely rusted metal where the gaskets seat. These surfaces are like a near polished smooth surface when they are factory new. So now eventhough the rubber gasket seats were not dried out, shrunk or cracked and all the small screws were tightly in place, the gaskets were no longer forming an airtight seal.
    The problem was that these smooth metal seats are factory pressed and spot welded into place onto the tank so I had to get a whole new tank. I paid retail at the local toyota dealer for a new OEM tank because there is a lot of work shoving around and fitting in parts to get the tank back in and I did not want to risk an aftermarket tank not fitting and seating perfectly after all the work of an install just to save a $100.
    It solved my problem for a year or so. Now at 220,000 during the summer or when I drive the truck hard I will get the same code so I learned to get my emissions sticker in january. First I reset the code then do a gentle 60 mile drive then go in for the emissions test. It passes then sure enough the next day the code is back BUT I'm good for a year. You guys that live in states with no emissions testing don't know how easy you have it!
     
    Last edited: Jul 1, 2014
  10. Jul 2, 2014 at 5:56 AM
    #50
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    That sucks that after a tank replacement the code is back... I'm beginning to think that the resistor trick seen in other forums might be the way to go as a permanent fix.
     
  11. Jul 2, 2014 at 5:45 PM
    #51
    Toyota-Dually

    Toyota-Dually Member

    Joined:
    Dec 28, 2009
    Member:
    #28321
    Messages:
    18
    Gender:
    Male
    First Name:
    David
    Holden Massachusetts
    Vehicle:
    TRD 4x4
    EVAP problems in cars and trucks over 10 years old is NOT just a Toyota thing by any stretch. And for states with emmissions stickers it starts to cost you so much time and money to fix that you have to buy something older or newer. Older because in most emissions states once your at 25 yrs+ you don't have to get tested anymore.
    The modern EVAP systems are so friggin' complex and full of little parts and seals and gaskets that it's like it was designed to fail after about 10 years. The problem the dealer told me is that every old parts starts to flex or stretch or just loose it's seal so it's almost impossible to track minor leaks.
    The other problem is that the pressures in the EVAP system feedback into the performance of the engine regulating throttle and RPM's so when the system leaks bad on really warm days you get sucky throttle response when you step on it and that's the part that bugs me most especially when I'm pulling my boat or horse trailer. This whole friggin' system is only designed to trap gas tank fumes. I don't get why just a carbon filter wouldn't be enough to do the job.
     
    Last edited: Jul 2, 2014
  12. Jul 3, 2014 at 5:22 AM
    #52
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    While the EVAP failures aren't only seen in Toyotas, I will say my experience has been Toyota is it is more prone to EVAP system failures. I have two old Hondas that have never thrown an EVAP error (2000 Odyssey and a 2004 Accord.)
    I've replaced three vsv solenoids in three various Toyota products, including my Tacoma. I'd like to keep my Tacoma for a long time as I like this truck, but it's no fun diagnosing CEL faults every few months. I made a connection with an EPA fellow in Washington a few years ago. I should send him a note on these failures. Toyota needs to design a more robust system..
     
    Last edited: Jul 3, 2014
  13. Jul 8, 2014 at 6:27 AM
    #53
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    Threw a CEL this morning after a couple of weeks. Seems to happen 50 or so miles after a fill up on my truck. I'm thinking of pulling the bed in order to get a good look at the top of the tank and the various evap related components. There's a gas safe gasket sealer that got good reviews (Gasoila PLS-2). This might be a cheaper alternative to replacing the tank. Also wish I had access to an evap smoke tester..
     
  14. Jul 9, 2014 at 5:54 AM
    #54
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    ok, I think I found the cause of my evap problems. I found some corrosion on one of the steel hard pipes that goes from the canister to the engine bay. There appears to be a pin hole from the corrosion. I cleaned it up and just wrapped it with electrical tape for a short term test. I'll sleeve it with a section of rubber hose and clamps if this proves to be the source of the CEL. The top of my tank, while rusty, didn't show any signs of seepage. I'll probably change it out before winter as I plan on keeping this truck for a long time. When I get a chance I'll post a picture of the corroded evap pipe.
     
  15. Jul 9, 2014 at 9:40 AM
    #55
    ugmold

    ugmold [OP] Well-Known Member

    Joined:
    Jan 26, 2010
    Member:
    #30066
    Messages:
    122
    Gender:
    Male
    Keep us posted on your findings.
     
  16. Jul 17, 2014 at 4:54 PM
    #56
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    I received the oem tank today and was surprised to see it was coated in bedliner spray on material. Toyota realizing a problem here? I'm hoping to salvage the check valve and the other component (evap port?). I did buy all new gaskets and a new filler neck.
     
  17. Jul 17, 2014 at 6:47 PM
    #57
    Mainmoe02

    Mainmoe02 Well-Known Member

    Joined:
    Apr 28, 2013
    Member:
    #103047
    Messages:
    2,055
    Gender:
    Male
    First Name:
    Moe
    Austin, Texas
    Vehicle:
    01 Gold tacoma SR5 TRD
    3" lift EIBACH coils w/ 5100's front, OME/ Dakar leaf springs w/ toytec adjustable shackles at 1.5" and 5125's out back. 33x10.5x15 KM2's Relentless DIY steel bumper.
    Subbed. I got a P0441 code about a month ago. I opened the gas cap then closed it hearing 3 clicks. The code hasn't come back so I'm praying that's all it was.
     
  18. Jul 18, 2014 at 4:08 AM
    #58
    ugmold

    ugmold [OP] Well-Known Member

    Joined:
    Jan 26, 2010
    Member:
    #30066
    Messages:
    122
    Gender:
    Male
    Who did you buy the parts from? What was the price?
    Thanks, and I hope it works I may follow suite.
    -ug
     
  19. Jul 19, 2014 at 4:58 AM
    #59
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    I bought it from Toyotaparts4less. Good people, helpful. The price was ~ $475, $50 or so shipping. I also bought a new filler neck as mine was looking rusty in places.
    So, I'm doing something I don't like to do, shotgun parts. But: 1) I don't have a lot of time to mess with this, 2) It's labor intensive to take down the tank, I don't want to do it multiple times, 3) It'll still be cheaper that having the dealer mess with it. My truck is very low miles, in good shape, so I don't mind investing some in it now. Cheaper than buying a new truck.

    Also my original tank felt pretty rusty on the top. That raised metal "Collar" by the check valve is crumbling.

    Be careful when shopping online for a tank. I did find a couple a bit cheaper, but shipping cost was very high.
     
  20. Jul 21, 2014 at 5:38 AM
    #60
    rosst

    rosst Well-Known Member

    Joined:
    Jul 23, 2011
    Member:
    #60373
    Messages:
    46
    Gender:
    Male
    So far so good. I filled up this morning and heard air released when I undid the gas cap. No gas smell when getting out of the truck after a 10 mile drive to work. Time will tell..
    I'm going to post a youtube video on a walk through of the replacement process as I did it, works arounds, lessons learned, etc.
    In hind sight, I think I could of reused my original gas tank by sanding the fuel pump, sending unit and check valve mating surfaces and by using a good gas tolerant sealer with new gaskets. I also replaced the filler neck, but the old one could have been reused with a good cleaning and paint.
    The tank strap was fairly crusty. I did reuse it after painting it with POR. But I think I'll order a new one and replace it before next winter.
    I also noticed the check valve hose clamp was completely rusted off. I replaced it with a new worm clamp. I don't think that was the cause of the evap leak, but it's possible. I'm into this repair for ~ $650. While expensive, it's still cheaper than having the dealer repair it. If I were to do this again, I would uninstall the tank, inspect and seal it up and reuse it. But live and learn.
     

Products Discussed in

To Top