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Having difficulty solving DTC p1456 on 1999 Accord

Old 09-11-2009, 03:37 PM
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Join Date: Sep 2009
Posts: 14

Originally Posted by jeffk14 View Post
Well, rjpjnk, I've bookmarked this thread, printed all the info and filed it away. Thanks again for all this valuable information!

As for my P1457 problem, the world may never know what the real issue was. This is actually my daughter's car and she drives the wheels off of it. She's now gone through probably over a dozen drive cycles now and the light hasn't come back on. Go figure.

The only clue I have is that last week, when I was checking things out, when I pulled the electrical connector off of the Vent Shut Valve, there was a small amount of rust/dirt that fell out of the connector when I took it off. I looked at the harness end and the plug on the valve itself, didn't think much about it, then plugged it back in after I finished my tests. Looking back, that may have been the problem.
You may be lucky and that fixed it!

fwiw, the Honda requires some very specific conditions before it will run this diagnostic, and it is entirely possible that you have not yet encountered them. The way to make sure it's fixed is attach your code reader and see if all the test for Evap Emissions System is marked as completed. If it's completed and you have no codes pending you're probably good to go.

If it's not yet completed you can force it to run by doing the following. All these steps are required or the test doesn't run. And it has to run the test and fail two times before the check engine light will illuminate.

(1) make sure the fuel tank is between 60-90% full. *Not* completely full.
(2) Leave the car off overnight or at least 6 hours.
(3) Start the car and go for a long drive on a highway at relatively constant speed between 50-70 MPH (5 mins ought to do, though I've heard as little as 1 min is sufficient). During this time try not to change the throttle position. Engine load must be fairly constant, so hills are not good either.
(4) Pull over and stop the car but do not shut the engine off, then go for another constant ride.

After this the test will have run. Check if the code is listed as pending, which means it has occurred once, or the MIL comes on, which means it has occurred twice.

It is important that between steps 2 and 3 you do not shut the car off! If you even start it briefly to move it out of the garage and shut it off you have to wait another 6 hours to test.
Old 06-16-2016, 11:40 AM
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Join Date: Jun 2016
Posts: 23

Originally Posted by rjpjnk View Post
Sure, I can help. I actually did take pictures showing the hole and the valve just in case. Is it easy to upload a pic here? Let me try later. I could also mail you one if you give me an email address.

I basically just cut from the fuel pump access hole up towards the back seat using sheet metal shears. I wouldn't want to do this on a new car, but the procedure for dropping the tank looked daunting. I think it will survive structurally. Patched with sheetmetal, screws, and silicone sealant.

Before you go and do that though, there is much you can do to test the ORVR valve. **Do that first** I would be happy to help you with the testing.

You have p1457, which means leak on the canister side. I believe it also means p1456 has passed, since it appears p1456 passing is necessary for the p1457 test to be interpreted based on how the solenoid valves are arranged in the circuit. If 1456 is passing, you don't have the leak I had.

To do any tests you need a vacuum/pressure pump. Do you have one? 35-55 on amazon. Buy or borrow that first.

Do you have the shop manual and tech bulletin updates for 1457?

There is only one hose from the canister to the ORVR valve, and you can easily disconnect it and plug the port to test.

What have you tried already?
rjpnjk, Seems like I need your help in case you are still following this forum.

I have outlined my P1457 in this thread :

and seems like I need to tear through the trunk to get to ORVR to replace it and the tube. Did you do both or just one?
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