2006 Nissan altima code p0420 2004-2006 Nissan Altima Factory Service - Auto … 2004-2006 Altima (L31) DESCRIPTION PFP OP CODE SYM DIA FRT DTC P0420 Diagnosis (1) START(Nissan) >> ENGINE >> ECM p0420 2006 Nissan Altima 2.5 -... Source Source Source Source Source Source Source Source Source Source Read Also: 2004 Nissan altima trouble code p0420 Engine code p0420 nissan altima Check engine code p0420 nissan altima 2003 Nissan altima code p0420 P0420 nissan altima 2006 Nissan altima code p0420