01 Sonata trouble codes
 

I have an 01 V6 Sonata that is experiencing the following trouble codes. P
0442 (evaporative emission control system leak, small leak) and P 0455
(evaporative emission control system leak, gross leak)

What are the odds of this being a problem with the gas cap? I have
cleared the ECM of all trouble codes and will give it another try. I have
been told to check the lines going to the charcoal canister as well. Just
glancing under the hood, the canister isn't visible. Where is it
located?

Thanks