Question

2003 Nissan Altima 2.5L with engine code P0420, how do I fix the problem?

Answer 1

HI there,

Normally to resolve the issue a new converter is required. You should contact the dealer with your VIN as there was a recall pertaining to the converter and if it hasn't been done on the car you may be getting a new one for free.

Answer 2

P0420 Nissan Code - Catalyst System Efficiency Below Threshold Bank 1
Read more: https://www.autocodes.com/p0420_nissan.html