[Sport]

Thought I had mine resolved with a new gas cap from Honda after two days of no error message. Then I got the message again. Super frustrating. I was told by my mechanic is was coming from the gas cap area based on test they did and after they taped down my old gas cap and no error was given.

I’ve attached a photo of my gas cap area. Could it be from the small gap you see on the left of the metal cylinder where gas cap goes?

Or is it time to check the purge valve and canister?

 

[mtts60]

It's time to have a look at the inside of the gas cap. There's a rubber gasket there that sometimes gets torn. Is it?

 

[Sport]

It's time to have a look at the inside of the gas cap. There's a rubber gasket there that sometimes gets torn. Is it?

It’s a brand new gas cap so no.

 

[visionguru]

...
Could it be from the small gap you see on the left of the metal cylinder where gas cap goes?...

If so, you should smell gas with the cap installed. It seems a Honda thing. My 07V6 gets check fuel cap message 2-3 times a year. Sometimes, reinstall the cap made it go away, sometimes, I had to repeat several times. Add some lubricant to the gasket should help. It might have something to do with vapor valve and the ECM software.

 

[Sport]

If so, you should smell gas with the cap installed. It seems a Honda thing. My 07V6 gets check fuel cap message 2-3 times a year. Sometimes, reinstall the cap made it go away, sometimes, I had to repeat several times. Add some lubricant to the gasket should help. It might have something to do with vapor valve and the ECM software.

I only smell a strong odor of gas when I remove cap. What type of lubricant did you use?

 

[visionguru]

Silicone grease

 

[Ronch]

There have been a couple of 9th Gen Accord TSBs for fuel supply problems, so check to see if your VIN is covered by any of them.

If you're getting MIL code DTC P0455 and/or P0456, this one might apply, depending on your VIN. Check if the (new) gas cap's gasket is black or brown. You should only use the newer one with brown gasket.

There was also a TSB regarding a gap where the neck of gas filler tube comes out from the body that could be related to the problem. Can't put my finger on it, but I remember that my '16 had to be inspected for the problem, but it didn't need fixing. Do you know if your car was ever inspected for this issue?

 

[Sport]

There have been a couple of 9th Gen Accord TSBs for fuel supply problems, so check to see if your VIN is covered by any of them.

If you're getting MIL code DTC P0455 and/or P0456, this one might apply, depending on your VIN. Check if the (new) gas cap's gasket is black or brown. You should only use the newer one with brown gasket.

There was also a TSB regarding a gap where the neck of gas filler tube comes out from the body that could be related to the problem. Can't put my finger on it, but I remember that my '16 had to be inspected for the problem, but it didn't need fixing. Do you know if your car was ever inspected for this issue?

First thank you for this great info. Much appreciated. I’ll have to check my gasket to see if it’s the brown color. I got it directly from Honda dealer. To me it seems like the neck of the gas filler has come out a bit creating that gap to the left. Could that be causing the issue?
I’m getting error code P0456 very small leak and have had the check engine light come on twice. My mechanic can’t figure it out as he doesn’t see any leak coming from the hoses or the valve.

 

[mtts60]

To me it seems like the neck of the gas filler has come out a bit creating that gap to the left. Could that be causing the issue?

If the gap is between the neck and body, then no, it is not the issue. The pressure is inside the filler neck.

 

[Ronch]

First thank you for this great info. Much appreciated. I’ll have to check my gasket to see if it’s the brown color. I got it directly from Honda dealer. To me it seems like the neck of the gas filler has come out a bit creating that gap to the left. Could that be causing the issue?
I’m getting error code P0456 very small leak and have had the check engine light come on twice. My mechanic can’t figure it out as he doesn’t see any leak coming from the hoses or the valve.

You're welcome!

Does your VIN fall in the range listed in that gas cap TSB for affected vehicles?

If you got an invoice from the dealer for the gas cap, check to see if it lists P/N 17670-TR0-A11 which is the failed part. Even if it doesn't list this number, that doesn't necessarily mean they sold you the right cap...

Since you're getting P0456, if it's not a bum/wrong gas cap, it could be a cracked/broken EVAP hose, or a failed purge valve.

Hope you get this fixed and post back with the solution...