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Old 03-17-2007, 09:23 AM
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BNaylor BNaylor is offline
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Re: Catalytic converter problem? (P420 code)

DTC P0420 is not normally an 02 sensor problem but a result of the rear 02 sensor doing its job by monitoring CAT convertor efficiency. It means the CAT convertor has less than desirable oxygen storage capability and low efficiency. Therefore, I agree you may have a flaky CAT convertor.

On the 02 sensor wiring the purple wire is HO2S hi and tan wire HO2S lo.



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