Why disconnect the battery and wait 5 minutes? That resets the computer... right? What I started doing was disconnecting the three harness connections on the computer. If you do that with the engine running, you will see that no matter which one you disconnect the engine will shut down. So, if you disconnect all three with or without the engine on, it will reset it. You will then have to drive 40 to 60 miles for the computer to find faults. I would say, check the gas cap. I had 3 codes. I found one hose on the solenoid was starting to fray, I changed it. Blow out that filter on the small round canister. My jeep was fine. After using the gas cap at autozone, I returned it because it would set off a code. So, I got the Stant Gas Cap from my friend's store. I haven't had ANY problems in 6 months. Also, make sure you check that the gas cap is tight, when you get gas. That is another cause of the problem.
I could have paid $200 to have someone detect the leak with a smoke test, I could have replaced every part from the canister to the valve and wasted $500. But I did a few things that costed less than $50 and solved my issues.