I hope I can bump this thread as I am on my wits end on resolving this issue as I can't pass state inspection. I've gone through 4 aftermarket gas caps and 2 of them shows large leak and the red check gas cap message, one said very small leak and my current one says small leak. Should I just go ahead and spend $90 on OEM gas cap and that will be a for sure thing as aftermarket gas caps are just not good anymore? The thing is I've had this issue each year for 3 years and a new gas cap always resolved it each year before state inspection, but this is the first time I had to go through so many gas caps and have not resolve the issue.

 

Are you sure the EVAP canister isn't leaking?

 

I did check. No leaks from there or don't smell anything. It is tight and secure. Unless there is some professional method I need to do to test it?