Subaru Repair: Catalytic Converter, catalytic convertor, conditional code

Question
My engine light came on and indicates catalytic converter.  What to do?  Federal government warranties company repairs under warranty?

Answer
p0420 is what is called a conditional code.Rather than a component code.Meaning that the conditions were present to indicate catalyst inefficiency .It does not mean the catalytic convertor has failed.A faulty 02 sensor ,excessive cylinder misfires,prolonged rich or lean fuel trim condition all can cause the same condition.The catalytic convertor is covered for 80k and very well may have an issue but the key thing to remember is that it failed for a reason and the cause must be diagnosed as well.The vehicle must be properly diagnosed by a qualified technician.If the cat and cat only is replaced chances are your little car may continue to pollute our environment.