P0420 Catalyst System Efficiency Below Threshold Bank 1

[Trane]

Hello

This code has unfortunately turned up on my car, 2008 Qashqai J10, 100k miles, Does anyone have any experience with this? Don’t fancy throwing money at a new CAT for it to be a 02 sensor nor do I want to replace good working 02 sensors when it’s a failed CAT.

Anyone had this issue before? And found the cause

[gloucester]

Welcome to this forum.

I haven't a clue but Googling threw up this topic which might enlighten you a bit:

https://www.nissanforums.com/threads/er ... ld.245650/

[calnorth]

Hello

This code has unfortunately turned up on my car, 2008 Qashqai J10, 100k miles, Does anyone have any experience with this? Don’t fancy throwing money at a new CAT for it to be a 02 sensor nor do I want to replace good working 02 sensors when it’s a failed CAT.

Anyone had this issue before? And found the cause

At a guess I'd say the CAT was a bit elderly...is it the original? Whats the cars mileage to date?

[gloucester]

calnorth - note he says 100k...