Sorry about not posting the state, I remembered that after I got off the computer. I live in Illinois, more closely the western suburbs of Chicago. This is our first and only OBDII compliant vehicle currently in the driveway.
Before I forget I also just installed Bosch Platinum spark plugs, Mopar Performance 7.5mm wires, drop in K&N filter, stock replacement Mopar Parts cap & rotor, and normally run Mobil 1 10w30 in the crankcase.
As for the gas cap, while talking to the parts guy at a former "official" Jeep dealership (still one of the best places to go in this area though), that for some reason, older gas caps seem to fail the Illinois Air Team gas cap tests. I never had that problem with the K-Cars I've owned, none of the other Jeeps we've had, and Mom's haven't had that problem either.