The A/C inlet is near your cowl and if you're only getting odor when the A/C is on then I'd say that you have a fuel leak under the hood. Check for leaks at your rails, injectors, regulator, and upper plenum.
Also look for an opening in the EVAP circuit. The fuel degrades the lines and the canister can crack. The canister is in the front passenger corner (kinda under the air filter area) and the purge line runs through the solenoid and to the underside of the front of the air plenum.
Yes check that charcoal canister!! I had a terrible fuel smell in my vert. pulled out the canister and turned it upside down, the charcoal that came out ( like sprinkles) reaked of fuel. Now no more smell.