P0420 Hyundai - how do i know which catalytic converter is it because it has two catalytic converter

Question

How do I know which catalytic converter when it has two in car

Answer 1

P0420 Catalytic below threshold

You have only one catalytic convertor, the code is listed as Bank 1 which also represent different engine sizes for a 2.0 it only has one catalytic convertor. P0420 mean its below threshold there can be also engine performance issue that can make it go below thershold such as worn sparkplugs ,vacuum leak that can cause a lean running condition and also a plugged airfilter.