I have the same issue. Were you able to figure out the line size and fix it? On mine it seems to be a little larger than 3/8" once you remove the rubber coating.

 

Anybody know the size of the male quick connect end for the steel evap line? Possibly 5/16's? The end of my steel line rusted out and it's throwing a small evap leak code. It's the line that runs to the evap canister and the other end runs to the purge valve in the engine bay. I plan to cut out the rusty end and use rubber fuel line with a new aluminum barbed male quick connect.

Thanks

Just going to point out that in your photo the quick connect has its size on it: 949.
I can confirm that my Element also has a quick connect size of 9.49. The rubber hose is labeled as 10x8, which I assume is OD x ID. I just ordered the parts to fix the same issue on my Element. I'll post an update if it's successful.

 

Hmmm, OK another thought. The garage told me (though I have seen this with my own eyes) the leak is a pin hole leak where the line goes over the gas tank. They used the term pin hole so I'm thinking what if...... I took spray under coating and shot it up in that area where it goes over the gas tank hopefully glomming on the pin hole and sealing it? No cutting splicing etc etc etc. It may not be the "correct" way to deal but ................

 

Update year and a half later, was code free until a couple weeks ago got a "check gas cap" message. No CEL, checked my ScanGauge 3 and said 456 code, very small leak. Wouldn't you know it right before my emissions test was due. Smoked it found the plastic union was cracked. It is 20 year old plastic after all.

Instead of spending $$$ on a new oem hose from Honda I just replaced the entire line with fuel line hose from the hardline to the evap cannister. Cost = $0 since I already had the hose & clamps. Probably should have done this in the first place instead of patching the line. Pardon everything looking goopy, woolwax to the max. Disconnected/reconnected the battery, 456 code disappeared and hasn't returned. Passed the emissions test with flying colors. Good till 2027. Seeya down the road.