DTC P0420: 3-Way Catalyst Function: Notes

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Using the following diagnostic procedure assumes the presence of a current (hard) DTC or the ability to duplicate the setting of the DTC using DTC confirmation test(s), intermittent recreation procedures or a test drive under conditions stored in freeze frame data. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM. If DTC cannot be duplicated, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom.