MBlake55

I was just wondering if someone could help me out and let me know what I can do to get rid of this check engine light. I used the OBDII code scanner and it came up as P1457 EVAP EMISSIONS, but the gas cap has already been replaced..................

- I have a 99' civic si, bone stock (except for an intake) and I cleared the code for evap emissions, which is the charcoal canister (I believe), located up near the firewall. The check engine light stays off for a few days and then comes back on, when the weather gets cooler out. Is there anything I can do to permanently get rid of the code? any help would be appreciated thanks

Vindicator9000

The only right way to permanently get rid of the code is to find the problem and fix it.

go to O'Reiley's, Carquest, Autozone, or similar and borrow an OBD2 reader. This is a little electronic device. Most of those places will allow you to use one for free or cheap.

Plug it into the OBD2 port and run a scan. It should give you a 4-digit code (might be something like P1457 if it's an EVAP problem). Find out what that code is and post it here.

Until you read that code, anything else we could tell you would be guessing.

Former User

I second what Vindicator says. With that said, some EVAP codes are thrown just because the gas cap seal is bad. Have a quick glance there while you are pulling the CEL codes.

MBlake55

ya ill have to scan the car and see what the code is, but the gas cap already got replaced and I might have to end up just dealing with this because a new evap canister is way to expensive to be worth replacing...........ill post up the code tommorow thanks a lot

MBlake55

bump code came up as P1457...........any help would be appreciated thanks

Redbone

did you try a different ECU because this also happened to me and I read that it could be caused by one single circuit for that control going bad.

ekb16

iTrader: (1)

there is 2 codes related to the evap...p1457 and p1456...p1456 is the gas tank area including the gas cap so since u have a p1457 it is the other half of the system..charcol canister area...most likey it is ur evap bypass valve/solenoid...i would replace those 2 and see if that clears the code otherwise u would have another issue

MBlake55

well i cleared the code and is hasnt come back on yet but f** it for now i guess thanks for the help tho guys

MBlake55

Okay so I erased the code again and it keeps comin back...........where exactly is the evap bypass valve/solenoid because I know where the black canister is, up by the firewall, (passenger side) and I looked at all the hoses today and no leaks, or cracks, but does anyone have a pic or can they explain where it is exactly, so I can get the check engine light to be gone permanently thanks for the help guys

ekb16

iTrader: (1)

MBlake55

thanks a lot for the diagram........I love honda-tech haha so many knowledgeable and helpful people on here, now should I just call up advance auto and see if they have the part, or does anyone know if this is a dealer only part (cuz the honda dealer always rips people off, mad expensive) -thanks

MBlake55

bump anyone?

MBlake55

anybody know where i can get an evap solenoid valve, other than the dealership, or what else would throw off the check engine code, someone was tellin me that any leaks near the filler neck could set the code off, but I dont know if thats true

Vindicator9000

BEFORE YOU START TEARING EVERYTHING APART AND REPLACING SOLENOIDS:

I chased this exact code on my 00EX for 2 years. I replaced just about everything evap related, and it was still throwing the code. I followed the troubleshooting flowcharts in the helms and all components checked out good - it was still throwing the code.

I eventually came to find out that my car throws the 1457 code 100% of the time if I overfill the gas tank, and that for some reason, the gas pump *NEVER* shuts off quite in time for my car - it may not spill gas out, but it fills it all the way up to the top of the neck. I suspect this happens to a lot of people, because I see a lot of questions on p1457 codes on 99 and 00 civics.

What has permanently fixed the problem for me:
When filling the tank, I'll run the gas pump full blast up to about 8-9 gallons, depending on how empty my tank is. Then, I'll run the last gallon on the pump's lowest setting. When I do this, the pump cuts off in time without overfilling. The key is to run the last gallon on low to prevent overfilling.

Once I started doing this on every fillup, I have never seen this code again, and it's been 2-3 years. I don't know why this fixes the problem, or why it's happening, I just know that this fixed it for me. Reset the code, run a few tanks like this, and see what happens. If that doesn't fix it, then change the gascap, and follow the troubleshooting flowchart in the helms.

Former User

This is excellent advice for anyone with an EVAP code.

Vindicator9000

OP: let us know if that fixes it. I'm curious if this is causing everyone's 1457 codes, or if mine's just a fluke.

I know that 1456 is normally gastank area, but I'm thinking for some reason an overfilled tank causes a 1457 to trip one of the other solenoids in the engine bay. Maybe causes too much vacuum in the fuel tank or something. In any case, my symptoms were identical to yours... didn't throw the code right away, seemed like it would wait until 1/4-1/2 tank to be gone.

MBlake55

thank you very much for the input, I knew i loved this website.........so basically ill just run it down to a half tank or quarter tank and then reset the code and when i refill it, just dont fill it up to the maximum full blast? and ill do that for 2 or 3 fill ups in a row and let u guys know if the code comes back on. Basically i could also just only put like 8 or 9 gallons in for every "fill up" and not the full 10 gallons and that should work also, correct? -thanks for the help man

Vindicator9000

yes, that.

ekb16

iTrader: (1)

after tryin to fix my p1457 problem for 6months it turned out to be my ecu EVAP circuit was fried casuing my purge sol. not to purge..replace the ecu and fixed

Utzz

So there was visible damage inside the ECU?

ekb16

iTrader: (1)

i never bothered to take the cover off the ecu and check..after following the flowchart for troubleshootin that code it says to replace with new or known good ecu so i found one cheap and surprisingly the code went away and my monitor finally set..thats how i got my jdm gsr to pass Bar

TheJediMex

gonna rebump this thread instead of making a new one.. im also having this problem.. any other suggestions?

jdmcertified909

yes you can figure out what is casuing the code to come on by following the diagnosing procedures outlines in the service manaul for that code. For that code, the first procedure checks the purge valve. It says to disconnect the vacuum hose from the EVAP canister purge valve and connect a vacuum pump to the hose. Then to turn on the evap canister purge valve with the Honda scanner or by connecting ECM connecter terminal B21 to body ground with a jumper wire, then to turn the ignition on and apply vacuum to the hose. If the hose doesnt hold vacuum, then the purge valve is ok, if it doesnt hold vacuum, then it goes to another procedure. The next procedure checks the electrical circuit for the purge valve. And so on and so forth untill the problem is found. this is how all check engine codes are diagnosed.

MeetTheFockler

Where can I get the service manual or TSB 99-074, "Diagnosing DTC P1456 and DTC P1457"? I changed the shut valve and reset the code. The check engine light came back on. I'm thinking about changing the Evap cannister next but would like to follow the diagnostic in TSB 99-074 before I spend more money.

Thank you.

TheJediMex

Any one else figure this out im about to give up and just chabge the whole dam charcoal canis