Novak Conversions Jeep Wrangler JK radiators

Smelling gas after filling up

Given the age and my experience, it's very possibly a small leak at the top of the tank (the seal under the fuel pump sender), a cracked emissions hose at/near the EVAP canister, or a possibly, a failed purge valve. These usually throw a CEL though as it should be doing the EVAP tests under specific fill-up/temperature conditions.
 
Novak Conversions Jeep Wrangler JK radiators