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darrell king
darrel ... 11/11/2012
2006 Nissan Maxima SL 6 Cyl 3.5L - Engine
i got a code po420 what ds this mean and should this be fix
1 Answer
  • CVO
    CVO 11/11/2012
    Trouble Code: P0420

    Catalyst Efficiency Below Normal (Bank 1)

    Possible Causes:

    Air leaks at the exhaust manifold or in the exhaust pipes
    Catalytic converter is damaged, contaminated or has failed
    Front HO2S or rear HO2S is contaminated with fuel or moisture
    Front HO2S and/or the rear HO2S is loose in the mounting hole
    Front HO2S older (aged) than the rear HO2S (HO2S is lazy)

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