P0420 is Converter efficiency is low.Hi,
Also, any suggestions for the P0420 code?
Catalyst System Efficiency Below Threshold. The catalyst system being referred to is your three-way catalytic converter; so the catalytic converter is not working properly (i.e. it's not efficient). So, to really simply things let's just say that the efficiency of the catalytic converter and/or exhaust pipe and/or O2 sensor is not so great.
BND Automotive LLC:driving: