P01456 Code Evap.

Discussion in 'Engine & Transmission Mods' started by GrubbyHonda, Aug 2, 2017.

  1. GrubbyHonda

    GrubbyHonda Active Member

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    2000 honda accord f23a4. stupid code keeps coming on. when i open the gas cap i no longer hear the vacuum sound from opening. so im sure i have a leak. gas mileage is still good. is that the evap canister? common fixes? maybe gas cap?
     
  2. RedRyder

    RedRyder Be a better driver

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    a p1456 leak is on the gas tank side, not so much canister, etc. So gas cap is the place to start, then fuel filler neck, and so on. I've had this code for a few years now but even after having the car smoke tested I still couldn't find it.

    Someone here said the gas tank likes to rust out on the front driver side so that would also be something to possibly check. Good luck.
     
  3. Connie

    Connie Well-Known Member

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    He's probably talking about me.

    Had this on both my 6gs and both times it was a rusted out tank.

    I had made a thread on how to change the gas tank but something happened to photobucket and now the pics wont show up.
     
  4. GrubbyHonda

    GrubbyHonda Active Member

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    so its fine if i just leave it the way it is? it wont do anything?
     
  5. Rusty Accord

    Rusty Accord Well-Known Member

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    I just checked my pics in my build thread (Members Rides) where I dropped the rear subframe out and changed the tank (pg4), and they're still there, so they might be of some help. I even had a pic or 2 of the seam rust, but I saw a pic where a member's tank had rusted out/thru in the low spot in the top front of the tank (left of center on the tank). In my pics, you can see where Connie suggested disconnecting the fuel lines at the sending unit/fuel pump cover. While I had the subframe and tank out, I cleaned up the rust on the sub frame, and changed both the sway bar bushings and end links (I used MOOG problem solver parts from Rock Auto, which is where I got my new tank).
    I had followed Connie's very well written write up, but had to deviate from it when it came to the rear brakes, as I have an LX with drums, and his write up was for disc brake cars and or a V6, while I have an I4. The big difference between the 2 is a handfull of bolts (or not having them in my case), and having to disconnect the rear brake lines/hoses on my own car. While others have used a trans jack or motorcycle jack, I just used my old heavy duty floor jack, as that's what I had available.
    I should mention here that it took me 2 afternoons to swap out the tank/subframe, but then I cleaned up my sub, and painted it while it was out, and I had to wait overnite for a brake hose that had failed (found it on reassembly), otherwise I had a majority of it done (while nursing a torn rotator cuff). It wasn't a bad job to do.
     
  6. Rusty Accord

    Rusty Accord Well-Known Member

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    The PO1456 code covers quite a few things. Honda says replace the gas cap first. Then it goes on to checking the fuel tank, fuel filler line and vent line, then it moves on to other parts of the fuel system (under the car). I didn't have a code 1456, but I did have a fuel tank leak (mine was in 3 places on the rear tank seam, and would make a big puddle of fuel on the ground, and the car stunk of fuel.
    Most times, it's the cap though. Keep in mind that a rusty fuel tank won't throw a PO1456 code. But, those of us in the northern climates are used to rust, and we know what it effects.
     
  7. Connie

    Connie Well-Known Member

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    I had the code for 3 years on Connie.

    I noticed no difference after fixing it, aside from not having a CEL, and I drive Connie a LOT. I only changed the tank because it was becoming quite the leak and I needed to get some exhaust work involving welding done.

    If you need to pass emissions, you still can without fixing anything; when you reset the code by unhooking the battery, it takes about 1/3 of a tank of gas for it to come back on. Your monitor for "evaporative emissions system" will scan as "not ready". You are allowed one "not ready" here in Ontario; as long as everything else comes back "ready", your overall result will still be a pass.
     
  8. Rusty Accord

    Rusty Accord Well-Known Member

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    Why didn't you just pull fuse #13 (passenger side fuse box) to clear the code? That what I did on my wife's car (2000 Accord) when I needed to clear codes whenever I did "engine related" work before I bought my nice code reader (I can clear codes with it), as it can read real time/live data. :)
    I think if you had less than a half a tank, you probably could clear the code, and then run it thru emissions testing and pass. I'm not 100% sure, as we don't have emissions testing here in Michigan.
     
  9. GrubbyHonda

    GrubbyHonda Active Member

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    my check engine light randomly disappeared today after i filled up my gas tank yesterday. maybe it was the gas cap?
     
  10. Connie

    Connie Well-Known Member

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    Hm, never even considered doing it that way, to be honest I didn't know that would work.

    I'll try it next time; thanks Rusty!

    I cleared mine with a full tank and it took a third of a tank to come back on. Plenty of time to get the emissions done; as long as no other issues exist, the car will pass as long as it's warmed up.

    Glad OP's code went away. Could be as simple as the full serve guys (or YOU, lol) being inattentive when putting your gas cap back on (loose).
     

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