P1456 code and fuel vapour leak

[shyste]

Ran into this problem at the shop this week. Try this, there will be a sensor on too of the canister that has 3 wires it's the fuel pressure sensor. Tap into the light green wire and monitor fuel tank pressure. With the key on and gas cap off it should have 2.5v, put the cap back on and start the car. The pressure should rise too 2.8 to 2.9v then shut the car off with key on. The pressure should stay steady for a while and not drop instantly. If it drops instant then you have a leak, start checking all line, rubber hoses, filler neck, fuel pump ect. Mine turned out too have a bad 2 way valve and the canister was flooded with gas lol. Lmk if you have any questions.

thanks for this! will try this upcoming week!

 

[xci.ed6]

Yea, could be...

Needa smoke test, or my 'ghetto' way sometimes works

Get ~1.5" rubber cap for pvc
Drill hole and somehow attach air hose
stick to gas cap tube
apply a lil air, it will leak
use SOAP in SPRAY bottle, it willo 'bubble' at leak

 

[shyste]

alright well i was suppose to do the fix that Immoral said. CEL ended up shutting off. for a awhile it was off then it came back on the other day. just got my bill to pay my taxes on my car and also have to get it inspected but the light is on. the warranty when triple A fixed it is way past and don't feel like dealing with them trying to get over to fix this. is there anyway to fix this so i can pass inspection

also went to advance auto and pulled the codes p1298 & p1456 .... and you can smell gas

 

[RedRyder]

For the 1456 you can try replacing the gas cap. If that doesn't fix it, a smoke test may reveal the source. Otherwise it's a troubleshooting game.

 

[james'99]

For the 1298, is it possible your ECM is shot? I read somewhere if you let these codes go, 1456/57, you can fry your ECM due to the nature of the circuit and that seems like what the 1298 means. Did you try erasing codes to see what comes back?

 

[xci.ed6]

got any links about the fried computer thing? I must know all!

 

[james'99]

got any links about the fried computer thing? I must know all!

http://www.6thgenaccord.com/forums/showthread.php?t=38000:

History:
I failed emissions because I got the code p1457 which points to evap canister. Now I know the evap canister hardly ever goes bad, it's normally the shut valve rusted open or shut. I got this code for the first time about 2+ years ago and I would normally just reset/erase the code anytime it would come on. The issue would pop up about once every 5 months or so. After a while, the the normal procedure stopped working. I figured it was time to fix it permanently. I've read, and it has been brought to my attention, HERE, that you could fry your ECU/PCM by simply resetting it every time or letting the issue go unchecked for an extended period of time. On the flip side I've read that it's a non issue. I would recommend that if you get a p1457 CEL once in a while and it doesn't come back on for months after resetting it, it may be a non issue and you can let it go for a while, but once the CEL comes on and continues to pop back up regularly after resetting it, then fix the problem.

http://www.6thgenaccord.com/forums/showthread.php?t=37764&highlight=p1457
http://www.6thgenaccord.com/forums/showpost.php?p=797975&postcount=10:

Unlike many other faults which set a Check Engine Light (CEL), this is one you DO NOT want to ignore. If a component shorts out, when the Powertrain Control Module (PCM, the computer that runs the engine) tries to activate the valve/solenoid, it instead finds a dead short...which can blow the transistor controlling that output. Once that happens, there’s no fix – except a new (expensive) PCM. Unfortunately, the EVAP system ‘runs’ whenever the PCM sees that the correct conditions are present – that means that it may run several times a day on 1 vehicle, and a lot less frequently on another, it’s all based on what the conditions are. Which is to say, one vehicle may have PCM damage happen quickly, while another may not. To avoid the possibility of ruining the PCM, its best to fix the problem as soon as possible. If there is damage and you do not replace the PCM, the CEL will never go away, and in many states that means you will fail the Emissions Inspection.

 

[bairdandrew77]

If you're willing to take a chance and spend the money, replace the gas cap. Use only OEM, none of the parts store stuff. I know from personal experience, they're going to keep throwing codes until you use a factory cap.

 

[xci.ed6]

interesting, if someone happens to have a dead ECM (assuming you replaced it with a good one) let me look.

I used to do ECM mods, I replaced the chip by soldering in a socket, then reading and rewriting the code to work with different injectors, MAP sensor, and boost.

 

[james'99]

If you're willing to take a chance and spend the money, replace the gas cap. Use only OEM, none of the parts store stuff. I know from personal experience, they're going to keep throwing codes until you use a factory cap.

I got away with flipping the seal lubricating and cleaning it till I could purchase a new one from a dealer. Made for a good test!

interesting, if someone happens to have a dead ECM (assuming you replaced it with a good one) let me look.

I used to do ECM mods, I replaced the chip by soldering in a socket, then reading and rewriting the code to work with different injectors, MAP sensor, and boost.

Now we have fancy things like Hondata Flashpro! Haha!