On 6 Mar 2005 09:01:47 -0800, "2confused" > wrote:

>For the past few months, I've been battling the following problem. My
>"check engine" light came on in my 2001 Toyota Camry (4 cylinder). The
>code, P0420, indicates that the catalytic converter needs to be
>replaced. Okay, the people at the muffler shop say that the front
>converter

snip...

There is an oxygen sensor before and after the converter. The
computer checks the converters efficiency by looking for a difference
between the two. No difference gives you a code that the converter
isn't working efficiently. I would suspect that one of your sensors
is not working properly and reading overly rich or lean. How many
miles on the vehicle? Original sensors?

Steve B.