2001 Nissan Pathfinder Check Engine Light

[umpquafred]

2001 Pathfinder Check Engine Light-- rented a sensor from AutoZone, resulting in codes 0420 (Bank1) and 0430 (Bank2) "catalyst efficiency below threshold" - Both banks at the same time? Could plugs or something in the engine result in this dual report? Suggestions?

[elwesso]

welcome to NICO!

It is probably related to your o2 sensors. Read the FAQ for more info, but basically the O2 sensors self destruct. Youll want to replace them and have your nissan dealer reflash the ECU, tis a well known problem.