P1456 code and fuel vapour leak

[RedRyder]

No one? Hate to spend more money for a shot in the dark, but I am thinking the 2-way valve is likely it...

 

[osageit]

Am chasing a double problem with 1456 code and a fuel vapour leak. Have looked at several posts on this forum, which were useful but will need some more advice in order to get this fixed.

Vehicle is 1998 Accord LX with 2.3 VTEC.

The car leaks raw gasoline fumes but only after the car has been running. The smell comes from underneath the vehicle, about where the rear seat is. The fumes dissipate after 20-30 minutes which suggests that the buildup of pressure in the tank is what is leaking out. Once the pressure leaks out, the fumes stop.

Along with this, the 1456 code activates but it is intermittent. Once I delete the code, it could be 2 months before it lights up again. It's not constant.

In trying to remedy the 1456, these parts have been replaced:
gas cap, canister, bypass solenoid and two-way valve.

Have done a visual inspection on the tank and hoses, nothing obvious although not everything can be seen well.

Thinking this through, it seems like it can be one of two things.

One - there is a physcial break / hole in tank or hoses allowing the pressure to escape even though the EVAP system is functioning (no 1456 or 1457 most of the time).

Two - the pressure is not getting evacuated by the system. Since the 1456 is not always activated, it would seem that the pressure sensor is functioning. Since there is no 1457 code, it seems that the purge solenoid is also working. Also, if there is too much pressure in the tank, the gas cap is supposed to release it. The fumes are escaping from under the car, not the gas cap.

The other ingredient is the dreaded ORVR valve on top of the tank. Not sure how it works and if it has any influence on the flow of pressure from into the EVAP system. Found a post on this forum on how to get at it but don't want to tackle this if not necessary.

Grateful for any insights on this one.

Found the real 6th Gen. P1456 EVAP Code problem, outside of the standard fuel cap solution. It's the two line on to of fuel pump cove; access thru trunk. Attached pictures.

 

[osageit]

If the fuel cap replacement doesn't fix your P1456 code take a look at the top of your fuel tank, port access thru trunk. Two fuel vapor line most likely leaking.

 

[RedRyder]

Changed my 2-way valve trying to rid the 1456. I’ve already done the gas cap, fuel canister, and shutoff valve. CEL came back on - again. I am at the end of my rope with this fawking 1456 code. At this point I’ve already spend $150, I don’t know whether to spend another $65 and change the solenoid or have the dealer look at it.

 

[001Stunna]

Changed my 2-way valve trying to rid the 1456. I’ve already done the gas cap, fuel canister, and shutoff valve. CEL came back on - again. I am at the end of my rope with this fawking 1456 code. At this point I’ve already spend $150, I don’t know whether to spend another $65 and change the solenoid or have the dealer look at it.

Do you hear the pressure release when you open your fuel cap? Does the fuel cap still have the rubber seal inside of it?

If the cap checks out then you'd have to take a look at the EVAP Bypass Solenoid or fuel tank vapor control valve...or it can be something such as a cracked hose.

Personally i'd consider paying a shop to do a smoke test on the system and you should be able to get it done at outside the dealer...or unless you have/know someone who has a smoke machine.

 

[RedRyder]

Do you hear the pressure release when you open your fuel cap? Does the fuel cap still have the rubber seal inside of it?

If the cap checks out then you'd have to take a look at the EVAP Bypass Solenoid or fuel tank vapor control valve...or it can be something such as a cracked hose.

Personally i'd consider paying a shop to do a smoke test on the system and you should be able to get it done at outside the dealer...or unless you have/know someone who has a smoke machine.

I do not hear the pressure release when I unscrew the fuel cap. Yeah the cap is new, the old one had the gasket as well and at some point I just stopped hearing the pressure release.

Is the solenoid you're referring to #7?

http://www.hondaautomotiveparts.com...EATHER)&catcgry4=KL4AT&catcgry5=FUEL+PIPE+(1)

I think at this point testing it is something to try, I can't just keep throwing money guessing at what's wrong. I tried the obvious fixes, didn't work. So that's the technical name, smoke machine? And I just tell the shop I'm trying to find a leak in the fuel evap system?


EDIT: I did see this slit in this hose, I filled it with some outdoor silicon sealant...

 

[001Stunna]

The EVAP Bypass Solenoid is #7 yes, or # 17012-S84-A01.

As you said, you've already replaced the common parts and unless you want to change all the evap parts to new only to find out it was really a hose(for example).

I would believe most shops would understand what you're talking about if you tell them you are looking to perform a smoke test on your EVAP system as you believe to have a leak and have been unable to pinpoint from where.

Have you checked the hose you sealed up with silicone to make sure the slit didnt grow or silicone wore off somehow?

 

[ShiftShapa]

I had the 1457 code and it turned out to be the Bypass solenoid valve which needed to replace. Although, my canister vent shut valve was pretty rusted bad (noticed after canister was removed) i changed the bypass solenoid and my CEL came on 2 days after the repair BUT when i reset it again the CEL never came on and my OBD scanner showed all passes.

i recommend doing the SMOKE Evap test first since your saying no pressure is heard when you release your gas cap. and then possibly change the solenoid valve.

My car is a 02 accord se.

 

[RedRyder]

Talked to a dealer out of curiosity to see what they’d charge to test the evap system/check for leaks. When did dealers start charging $90/labor hour? That’s pretty ridiculous. Going to look into a shop that will do the same thing for less.

Have you checked the hose you sealed up with silicone to make sure the slit didnt grow or silicone wore off somehow?

I felt it while I was under there, still seemed intact from when I sealed it up. I am kind of in the mindset now that if nothing else I’ve replaced was bad…the solenoid wouldn’t be either. Plus it’s inside that plastic casing. But that may be my frusteration talking.

I had the 1457 code and it turned out to be the Bypass solenoid valve which needed to replace. Although, my canister vent shut valve was pretty rusted bad (noticed after canister was removed) i changed the bypass solenoid and my CEL came on 2 days after the repair BUT when i reset it again the CEL never came on and my OBD scanner showed all passes.

i recommend doing the SMOKE Evap test first since your saying no pressure is heard when you release your gas cap. and then possibly change the solenoid valve.

My car is a 02 accord se.

I have 1456 though. Wish I had the 1457 lol, seems like it’s easier to fix. In fact I bet one of the three things I’ve replaced already would have solved that one. Thanks for the recommendation though.

 

[schmiddr2]

I also have a P1456 code. It's even worse than most people's because the damn fuel pump runs even when the car is not running. But it in no way effects the driveability or performance of the car, so it's more of a nuisance. That is, at least I can't imagine this issue getting to the point where it could leave me stranded on the side of the road.

I hate that this P1456 is like a mystery for everyone to solve. But I do have a question if any knows this; which sensors can tell the ECU to trigger a P1456 code?