99 Accord EX 4 cylinder Automatic 115k miles

Getting a code P1456. Leak in the EVAP system. I checked on top of the fuel pump (in the trunk), everything looks ok and no gas smell at all. I looked under the car (next to the gas tank) at all the hoses, etc. and everything looks fine, nothing seem to be loose, leaking, holes, no gas odor. I inspected all the hoses under the hood and everything looks ok. I had my gas cap tested at the smog shop and it is working properly. I reset the check engine light and it comes back on.

What should I try replacing first? The canister, the canister vent shut valve, or the 2 way valve? Or anything else? I will try replacing them one by one to see if they will fix the problem. I want to avoid replacing everything unless I have to because I'm on a budget. What is a good/cheap site to get the replacement parts?

If you need anymore info, please let me know. Thanks!

 

You can pull off the check valves and check them with a vacuum gauge. Or if you don't have a gauge you can blow the ends the see if you air moves. Other then doing self test on the system using a nice scanner you only can do a smoke machine test to see if there is a leak in the system.

 

You tried to find the leak by sniffing for it?LMAO!!! The code will set for a leak 20- 40 thousandths of an inch in diameter. You aint gonna smell that son. You need to get the system smoke tested. And if no leaks are found,further testing will be required....
P1456 is specific to a fault in the gas tank side of the evap system only.Dont sweat the canister side....

 

What check valves? And any info on how to test it? I can rent a vacuum gauge. I will also rent a smoke machine and test the system.

Any other tips?

Thanks

 

Thanks for the info. So what should I try replacing first?

Thanks

 

As stated above have a shop do a smoke test.


A evap leak tends to leave a oily type film around the leak. Looks kinda wet. You see anything like that?

 

I will have it smoke tested and will post the results shortly.

I didn't notice anything oily or wet.

Thanks

 

even tho its gas tank side unless it a hole in the vent tube from the tank. ive always seen the bypass valve go on these,and since your in there id do the vent valve and the 2way bypass valve,your screws seemed like they arent as rusty as others,usually have to replace them cause they rust in and break on the vent valve

 

Thanks for the info. I guess I'll start with the 2way bypass valve then the vent valve.

 

Problem solved.

After checking all the vacuum lines and evap components under the car, I reset the CEL. Drove it for a hundred miles, the light didn't come on so I went to smog my car and it passed.

During my inspection I tightened all the lines. Maybe that fixed the small leak. I didn't have to replace anything and I didn't use a smoke or vacuum tester.

Thanks everyone