Why Does My Ford Show P0430 Code? Is My Catalyst Converter Failing?

[Nicko]

I’ve got a P0430 code (Catalyst System Efficiency Below Threshold) on my 2015 Ford Explorer. Do I really need to replace the catalytic converter, or could something else be causing it? I’ve read online that sometimes it could be the O2 sensors? Trying to avoid a big bill if possible.