Question

2002 Infiniti G20 with code P0420, will replacing the oxygen sensor fix the problem?

Comments

Most likely not, the catalyst converter needs to be replaced

Answer 1

The cat does npt to be replaced unless the co2 levels are out of wack. The one that is most likely nad os the one right.before the cat conv.while its job is to fluctuate its probably just staying steady therefor you get a p0420 code

Answer 2

P0420 INFINITI - Catalyst System Efficiency Below Threshold Bank 1

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