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P0420 Code

Kam101k
Kam101k
in Ford Focus Club

Featured Replies

Hi folks!

Looking for some advice.

I got the P0420 code stating "Catalyst System Efficiency Below Threshold Bank 1" and was advised to change the oxygen sensor, my question is what size tool would i need to remove this? I've noticed that there are two sensors next to each other and was wondering which one would need replacing? Left or right? (I have attached pictures)

Also, if anyone here has had a similar issue..does replacing the sensor help the problem?

I have a Ford focus, 1.6 2005 petrol model.

New to all of this so i am learning as i go along...Thanks in advance!!

20200711_120643.jpg

  • Quote


    Possibly neither, it could be as the code suggests that the catalytic converter has failed. If that's the case then you need to establish why. What diagnostic steps have you undertaken. for example monitoring live data? Readiness monitors?

    If you have no idea what those are, let me know and I'll go through it with you, but I wouldn't go replacing those just yet.

  • Quote
    • Author

    Hi,

    Apologies for the late reply and thanks for responding!

    The only thing that I have done is plugged in my OBD2 reader and it gave me the code and also did a live reading to check to which I have posted a couple of screenshots...I'll happily go through more checks if required.

    The only fail that came up was for the catalyst mon b1. 

     

    rsz_20200717_195140.jpg

    rsz_20200717_195124.jpg

    rsz_20200717_195127.jpg

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