Gascap notification, P0455 & P0456 keep happening. Related?

[volkey]

So on my 2008, I keep getting the Check Gascap notification.

I also intermittently get P0455 (EVAP SYSTEM LARGE LEAK) and P0456 (EVAP SYSTEM SMALL LEAK) which I can reset with my Diablosport Intune.

It's been driving me insane but I'm not sure where to start trying to find what's causing the issue.

I'm wondering if these are related issues, and if maybe my car hasn't had the gas tank recall/fix and that might be the cause. Anybody else have suggestions on what to look at?

[StrokedRT]

When mine did that, I ended up replacing the evap canister in the rear wheel well. Solved it. No more codes.

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[Root66]

Me too, had to replace the ESIM.

A Closer Look: Evaporative System Integrity Module (ESIM) - YouTube

[osirisx69]

Same, it was the evap charcoal canister inside rear wheel well. That was after about 4 new gas caps....

[GLHNSLHT2]

My daughters 09 SRT4 had this code when we bought it. I'm not sure if it's the same as on the LX cars but there's a electronic box that attaches to the EVAP canister with a large vac hose going to it. This valve must move and hold vacuum during certain conditions. If it doesn't do it 3 times in a row under the same conditions it sets the code. You can replace just that box for like $40. It fixed my daughters car. Probably the same thing on LX cars too.

[68reaper]

got the same problem with my 2007 charger SRT8.
P0456 P0455 sometimes the lose gas cap on the screen.

so i got already 3 times on a smoking machine but still cant find the problem.

first parts i replaced was the
- gascap
- EVAP purge solenoid under the hood
- the white leak detection pump on the carcoal canister in the rear right wheel
- and the vapor filter attached to it.

all lines look okay and no smoke visible got the rear seats out and everything looked fine no smoke on the gastank.

im thinking to replace the carcoal canister that is the last part i didnt replace??

if you guys can help me out thanks a lot! drives me crazy!

[cleary524]

I did all the easy repairs to my EVAP system. My code ended up being an evap tube on top of the gas tank. Mice chewed thru one of them. I was having the gas tank removed and replaced under warranty when the EVAP tubes were discovered to be chewed. Crazy!

[WLGeter]

I did all the easy repairs to my EVAP system. My code ended up being an evap tube on top of the gas tank. Mice chewed thru one of them. I was having the gas tank removed and replaced under warranty when the EVAP tubes were discovered to be chewed. Crazy!

Did you end up just replacing the fuel tank filler neck because of the evap tube leak on it or did you end up doing the tank and the FTFN?