I have a 2005 Nissan Altima 2.5 with code P0420, failed emissions test. what is the cause?

Question

I have a 2005 Nissan Altima 2.5 s with code P0420, failed emissions test. what is the cause?

Answer 1

This code is for the catalytic converter. Typically the converter is no good and must be replaced. Contact the dealer to determine if there is a update for the ecm to resolve the code before replacing the converter.