Engine Diagnostic Light on... (What does this Diagnostic code mean?)

  1. Established Member Joined: Mar 2010 Bradford Posts: 1490 '02 VTR, '92 106 XSI 16v
    #1
    Over the New year, my Engine Diagnostic light came on and stayed on. So, i decided to buy a 'Autel scan diagnostic tool' from ebay and scan it myself. (Can't go wrong for 20quid!)

    So i plugged it in and i received the following code:


    P0420 - Catalyst Efficiency Below Threshold (Bank 1)


    What does this mean in english?
    Anyone else had the same problem?

    Also, i have the option to erase the fault code? what will happen if i erase it?


    I presume it's to do with the cat converter.. could it be a sensor? or just a very tired cat?

    Any help apreciated!
    thanks!

    EDIT: I Have a MK2 Saxo VTR And still have the original manifold, so my CAT converter is in the manifold. But i have got a cat-back supersprint/kam racing system (if this helps)
  2. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #2
    It means you CAT has either had it or is nearing the end of its natural life mate.If you erase the code but don`t repair/replace the faulty part then the light will come on again,the same will happen if you replace the part but don`t clear the code(hope this makes sense)
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  3. Established Member Joined: Mar 2010 Bradford Posts: 1490 '02 VTR, '92 106 XSI 16v
    #3
    Quote:
    Originally Posted by stevo67 View Post
    It means you CAT has either had it or is nearing the end of its natural life mate.
    Ah right thanks

    I'd love to take this as an excuse to get a 4-2-1, but probably not ideal with my MOT coming up. New CAT it looks like then
  4. Saxperience Post Whore Joined: May 2009 Birmingham Posts: 5801 1.1 106 XN Time, MK2 VTR 01. Ford Focus ST3 CP320
    #4
    why dont you clear the fault. Pass your mot (Hopefully) then if all is Well, get a mani.
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  5. Saxperience Forum Bum Joined: Sep 2010 leeds Posts: 4389 MCS R53 S/C 16v furiooo
    #5
    when's your MOT?

    could borrow mine if yours doesnt pass as it's sat in the garden since i put my 421 on lol.

    a mate mentioned someone wanted to buy it though so if it's quite soon sure it would be ok?
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  6. Established Member Joined: Mar 2010 Bradford Posts: 1490 '02 VTR, '92 106 XSI 16v
    #6
    Quote:
    Originally Posted by Carlvtr88 View Post
    why dont you clear the fault. Pass your mot (Hopefully) then if all is Well, get a mani.
    Never thought of this tbh! I will try clear the code in the morning.. see what happens



    Quote:
    Originally Posted by mlawlan69 View Post
    when's your MOT?

    could borrow mine if yours doesnt pass as it's sat in the garden since i put my 421 on lol.

    a mate mentioned someone wanted to buy it though so if it's quite soon sure it would be ok?
    Thanks for the offer mate but my MOT isn't as soon as what i thought it was. Thought it was back end of Jan, but looked today and its back end of Feb! cheers anyway
  7. Established Member Joined: Mar 2010 Bradford Posts: 1490 '02 VTR, '92 106 XSI 16v
    #7
    Just found this on Google
    http://www.obd-codes.com/p0420

    So might just be a leak somewhere (hopefully), I'll look into this on the weekend
  8. Infrequent Poster Joined: Jan 2011 queensbury Posts: 146 Black saxo vtr
    #8
    Iv got a cat pipe for sale like new I'm in queensbury if ur interested
  9. Frequent Poster Joined: Oct 2010 Blackburn Posts: 595 Citroen Saxo VTS
    #9
    My EML come on 2 weeks before my mot, had the same problem as you

    cleared the code and it passed the mot without and problems with emissions first time

    i would keep the money for a new cat, and just send it in for the mot and see what happens (maybe see if you can get them too pass it even if its fails emissions. if you get my drift)