# P0420 Catalyst System Efficiency Below Threshold (Bank 1)



## tieggonzalez (Apr 22, 2007)

Code P0420 Catalyst System Efficiency Below Threshold (Bank 1)

Hello everyone. I need some help finding a solution to this code. My hope is that the catalytic converter does not need to be replaced.

My car is a Nissan Sentra GXE with 158,000 miles.

Has anyone ever seen this???


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## calvic08 (Dec 23, 2008)

I have the same problem on my Altima 05 with 132K mile on it. been having this code for month now. Help please....
Thanks


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## tieggonzalez (Apr 22, 2007)

Unfortunately, I cannot be of any help to you. The error just went away and has not returned in 20k miles.


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