Yep... TBJ has a pretty solid bet there..
This has been discussed over and over on here, the EVAP code seems to be the most common one KJ owners fight. Mainly due to the age of the rubber hoses and cracking becomes pretty common. Follow the EVAP canister lines from in front of the gas tank to the front, goes up to the EVAP solenoid by the battery.
That reminds me also check the hoses where they are connected to the EVAP solenoid, that caused the leak code on a couple that posted on here as well!