So it says, po456 evaporative emission system leak, (very small leak). Only 30k on the truck and am leaning toward the locking gas cap to be the issue. Anyone else out there have locking stant gas caps go out? I reset codes today and will keep an eye out for another one. A new cap is 15 bucks and an easy fix but a few months back they did replace my plugs and messed up my a/c. To soon to tell. Will post back when I get some daylight time away from work to try and figure it out. Thx for any feedback.

 

So I cleared the code. Inspected the gas cap and re installed. No codes yet.

 

I recently got this code on my 2003 Jeep TJ... It ended up clearing on its own after a few days but has since come back. I am going to replace the gas cap - its a cheap enough fix to see if it will solve the problem.

I had the same code on my Dakota years ago and it was also solved by replacing a gas cap. At that time I had heard that Chrysler's gas caps were notorious for causing this problem.

Other than that it is inspecting a lot of hoses which I really don't want to get into.

 

It may not be the gas cap, It could be either the NVLD or ESIM pump not switching. Did the loose gas cap code show up on the cluster?