Code P0456 - the ol' EVAP leak - what should I check?


Hi all,

Last week, in the first 2 or 3 minutes of driving our (well…my wife’s…I don’t like to take ownership of this vehicle :slight_smile: 2001 Grand Caravan (3.3L V6, 140K kms), the check engine light came on. It wasn’t blinking and everything seemed ok, so we drove on, and it’s been on since.

Finally got my code scanner today and pulled code P0456 - “EVAP Emission Control System Leak - Very Small”.

I know this usually means the gas cap, so should I just first replace that with one from the dealer? Or is aftermarket ok?

Or is there something else I can/should check for this leak?

Wondering if it’s even worth getting the gas cap for such a small leak but you’re the experts…interested to hear what your opinions on this error are.






Before you replace anything, inspect the cap and filler neck. Make sure the rubber gasket/oring on the cap is clean and pliable. Check the sealing surface on the filler neck for debris and/or corrosion pits. Then make sure the cap is properly seated and clear the code. It takes several drive cycles for this monitor to become ready so be patient. If it persists, time to look deeper.

 Checking it first for any visible problems as Twin suggested is a good idea.  After that I would likely go for the OE cap, but in reality there is little reason to prefer it.  Remember that unless your scanner resets the code, it could take server days and a number of driving cycles for the light to go out.  

 As for ignoring it, I would not worry so much about the leak, but I would worry that because if it, I would not know if any new problems came up.  They might be more important.


Thanks guys. I’ll check those and replace the cap, clear the code and see what happens. If it ends up sticking around, I’ll just make a habit of plugging my scanner in every once in a while to see if there are new codes.