OpulentSpider

I recently replaced the vapor canister vent solenoid on my 02 civic LX to address a P1456 code. Check engine light was off for a couple hundred miles but just came back on, this time reading P1457.

Seeing that this might be related to the purge solenoid valve on the vapor canister. I’d prefer not to replace that because getting the vent solenoid replaced was a nightmare with how rusted the screws were, but if that’s what it takes to clear the code I guess I’ll have to replace it. Also seems like a huge coincidence that I just replaced the vent solenoid and the purge solenoid valve happened to fail two weeks after.

It should also be noted that the electrical connection on my replacement vent solenoid didn’t snap in and is held on by duct tape, but I made sure the connection was still good and the check engine light is still on.

Is the P1457 code definitely the purge valve? How should I go about fixing it?

Colin42

What brand is the new part?
need to make that electrical connection proper

BrotatoChip

Check out this thread:

https://www.civicforums.com/forums/3...-fuel-cap.html

OpulentSpider

Didn’t see this before I posted, just what I was looking for. Just ordered the purge valve so hoping that works like it did in this person’s case. The hours I would spend checking for an unconfirmed leak would definitely be more than the $30 part.

I had the intake off while I was cleaning the engine bay so very possible that is it.

OpulentSpider

Dorman from Amazon, took the cheap way out. Going to double check the connection today.

Colin42

Cheap part may be the problem, check the other things first

OpulentSpider

Just replaced the purge valve and that didn’t fix it. I have also noticed the smell of gas while sitting idle after driving. Connection to the vent solenoid seems fine.

Colin42

Rust belt?
also have a look at the top of the fuel sending unit and see if it's cracked (remove rear seat bottom and access panel)

OpulentSpider

Yup, rust belt. Checked out under the seat earlier and didn’t see anything that looked broken. I don’t have a smoke machine but my plan now is to send compressed air through the system and hit suspect points with soapy water.

Colin42

You looked at the top of the sending unit? No cracks?
yeah probably one of the solenoids is rotten

OpulentSpider

Instead of typing what I’ve done the last few hours, I’ll give you the TLDR: I am pretty confident this hose or what it connects to is the source of the leak.



This connects to the top of the canister. Not sure what the white assembly is. I want to just replace the hose and see if that works but my hands are too big to get above the tank to remove it.

OpulentSpider

Here’s what I learned in my 4 hours of work today:

1. All fuses are good
2. Canister vent solenoid actuates and gets power
3. The canister and vent solenoid have no leaks (pulled it and tested it independently)
4. The valve solenoid on the other side of the canister mounted to a bracket was recently replaced (new bolts and part looked new)
5. Vapor line from purge valve to canister holds pressure
6. No visible leaks on connections to canister with soapy water, but could not check the plastic one on top that leads to above the tank
7. No cracks on fuel sender, no leaks
8. No leaks on filler head
9. Before the system hit 5 psi, the gas cap (new) would begin to vent
10. Some corrosion on parts of the fuel line and vapor line but no visible leaks. Just went through replacing all the brake lines but they are nowhere near that bad.

I am suspecting the plastic tube on top of the canister, but cannot find a diagram of it anywhere so I don’t know it’s function.

BrotatoChip

Do you have a handheld vacuum pump and a multimeter you can use for testing? I can send some instructions if so.

OpulentSpider

Yes, I do

BrotatoChip

I will try to put some test instructions together today.

BrotatoChip

P1457 troubleshooting, based off the troubleshooting in the RSX service manual since they should be similar. It's been a while since I've had a troubleshoot one so hopefully there are no mistakes.

First, find the EVAP canister purge valve (number 2 below). Connect your vacuum pump/gauge up like the red arrow. Leave the hose connected that goes to the throttle body (connect to the other side of the valve). Ignition on. Enable the valve by shorting ECU pin B21 (yellow/blue wire) to ground, you should be able to hear the valve click. Try to pull a vacuum, does it hold? (it's not supposed to). If it does not the remove your ground jumper and try again, it should now hold a vacuum. That step is not included in the troubleshooting but confirms the valve is normally closed. I spent so long trying to find the P1457 cause on my CRV because that step wasn't in the troubleshooting.


Next we're going to check the EVAP bypass solenoid (two way valve). Hook up your vacuum pump like below, try to pull a vacuum (ignition still on). If it holds it's good.

Next we'll check the canister vent shut valve. Connect the vacuum pump to the canister vent filter line as shown below. Ignition on. Turn the valve on by shorting a pin to ground again. I can't find it in the Civic service manual but the RSX one says pin E21. Try to pull a vacuum. If it holds, it's good.


Next test the canister for a leak. Add T fittings, the pump, and cap the canister vent valve as shown below. Turn the ignition on and try to pull a vacuum. It may take quite a few pumps for the vacuum to build up.


If that passes the next step it says is to inspect the EVAP canister vent shut valve line and connections. When running through these tests stop if it fails any of them and report back.

bbynams

I can tell you the canister is (somehow) internally divided if you're assuming otherwise. Pictures at this location: How to troubleshoot a P0497 and P1457 EVAP code? - Honda Civic Forum (civicforums.com)

bbynams

It looks like the tank fumes flood about 2/3 of the capacity and are either purged or pulled around through the canister vent (assuming it hasn't rusted shut).

OpulentSpider

Two way valve did not hold a vacuum. Thought the part was new because of the fresh bolts mounting it but on closer inspection it looks like someone just used glue to seal the original part as a temporary fix.

BrotatoChip

You can check a few things electrically if you haven't already replaced it. Check continuity through it, don't know what exactly it should read but it won't be open. On the connector side, one pin should have ground.

OpulentSpider

Already replaced the part, will the code clear on its own?

BrotatoChip

If the problem is fixed it should eventually. Probably easier to just clear it or disconnect the battery for a few minutes to reset.

OpulentSpider

Reset but after about 100 mi CEL is back on. Smell of fuel in the cabin is pretty potent when I idle after driving.

BrotatoChip

Have you checked the fuel pump housing? We have seen them crack before and will cause fuel smell inside the cabin. It will also cause an EVAP code.

OpulentSpider

Checked the housing under the rear seat and didn’t see any cracks, also had some soapy water on it when I had the system under pressure and didn’t see anything. Could I have missed something?

NDNV

FWIW, replacing the By-pass (Canister) Shut Valve (CVS) and canister solved the P1457 code I had years ago. I used OEM Honda parts.

OpulentSpider

Cleaned it off, definitely the housing.

BrotatoChip

Good find. I would have expected to see a P1456 instead of a P1457. Get it fixed then see what happens.

OpulentSpider

CEL is back on with the same code after a drive cycle. At least the smell of gas is gone while idling (now it just smells like exhaust from a leak I haven’t gotten to yet).

I don’t have T fittings so I never checked the canister with a vacuum pump but like I said I had it off and tested it independently and it held 5 psi.

The tube I posted a pic of previously on the top of the canister (fuel vent tube part 17725-s5a-a32) was giving me problems reconnecting it and seemed like it was possibly not sealing. I’d replace it but it’s $50 so want to avoid that.

BrotatoChip

I would recommend getting some T fittings to finish testing or take it to a shop for troubleshooting. There is also some general EVAP troubleshooting in the service manual available at the link below, I think it is basically testing the same things and also requires T fittings. This starts on page 11-163.

https://www.civicforums.com/forums/1...pdated-13.html