2001 Impala SES Code P0420

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Dave

2001 Impala SES Code P0420

Unread post by Dave » Sun Feb 07, 2010 7:56 pm

Got a 2001 Chevy Impala. Autozone scanned for a check engine light.
Code is P0420 catalytst inefficient.
They said I need a new cat. converter.
Have read on some other forums that it copuild be the EGR or Mass air flow sensor, but i don't have codes for those. Can those sensors still be the problem?
48zadnp

Meccboy

Re: 2001 Impala SES Code P0420

Unread post by Meccboy » Mon Feb 08, 2010 12:14 pm

If either the airflow sensor of one of the oqygen sensors were bad, there would be a code for them.
Even if there were codes for those sensors, a faulty catalytic converter can CAUSE theose codes.
When a converter is plugged, it will affect oqygen sensor readings, as well as the MAF.
This sounds like a bad catalytic converter.

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