Once you apply for CAP and have your Hyundai's smog check failure is diagnosed by a Gold Shield smog station (at the State's expense) and it is determined that the fault is in fact the CAT, the State will pay the remainder of the $500.00 CAP dollars towards a new Catalytic Converter and ask you to pay the balance.
If you can not afford the balance you will need to submit to the State Smog Check Referee Office for a smog check waiver. A CAP Gold Shield will explain to process to you once your Hyundai Elentra is accepted into the program.