troule code p0420

HONDA CIVIC
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VEVEYA
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1997 honda civic 100040 mileages.
my check engine light was on. the diagnostic trouble code is P0420------ Catalyst System Efficiency Below Threshold (Bank 1) , one repair technician told me I should replace a new catalyst converter, but another one told me to replace the new O2 sensors, what should I do? thanks.
Aug 13, 2006 at 11:59 PM
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SERVICE WRITER
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Have someone check the 02 sensor wave patterns on a scope or for being out of spec. In particular the front one. Converter is probably fine,but further testing should be done. If testing was done, not just a conversation, then you'll need to have faith in one of the techs. That code points to bank1-02 sensor. The front sensor evalutes gases before entering the converter and the rear one evaluates it after the converter
Aug 14, 2006 at 10:13 AM