I have a 2005 Dodge Ram V6 1500. My computer started showing a P0456 - Small Evap Leak code around November. I've tried everything I can think of an can't seem to get an answer or a fix. So far I've done the following:

• Replaced the gas cap
• Smoked the truck
• Visually inspected the lines
• Inspected the evap canister

Nothing shows any signs of issue and the smoke test came back clean. Luckily I have a great mechanic who so far has only charged me $90 for all the above diagnostics. At this point he seems to think there is an issue with the computer. I've already reset it twice and the code comes right back on. He seems to think he can "re-flash" the computer to fix the issue.

Does anyone have experience with this issue? Could it be the computer? Is my mechanic blowing smoke about "re-flashing" the computer?

P.S. - I'm getting a little desperate because my inspection expires at the end of the month and I can't get it renewed with the computer throwing codes.

 

Did you check the Leak Detection Pump itself? Maybe it has gone bad?

 

When my truck had this code it was a small split in the hose on the leak detection pump

 

Yeah, this likely isnt going to be a mechanical issue but rather a physical one. Check ALL the hoses at the evap can in front of the fuel tank also.

 

i had the same issue, p0456 evap. emission system leak, very small leak, IT WAS MY LOCK GAS CAP, i installed the factory cap & never had that check engine light come back on,, if you bought a lock cap, even from the dealer because thats where i bought mine, change that first, my mechanic told me that for some reason the ram 1500 trucks do not like them, he has had more of this same problem with the ram trucks,, i hope this does the trick for you as it did mine,, good luck,

 

that works most of the time...another thing to look at is the evap hoses under the truck. maybe take em off and inspect them. sometimes they will have very small slits and holes. replaced those on my uncles 1500 and problem solved hope this helps future readers.