Honda Car Forum

#1 (**permalink**) 31 Oct 2003, 05:16 pm

Took daughter's 99 Accord LX (4 cyl) to Autozone for CEL check. Their
rudimentary device gave this code and message:

Code 0420: The PCM has determined that the catalyst system efficiency for
bank 1 is below threshold for the current engine operating conditions.

I suspect front O2 sensor based on some research I've done on the web. Any
ideas, other than paying the dealer $75 for the full diagnosis?

Thanks...TH

#2 (**permalink**) 01 Nov 2003, 12:56 am

"Strorg" <strorg@strorg.org> wrote in message
news

b6dnSmMk5S9Qj-iRVn-gg@comcast.com...
> Took daughter's 99 Accord LX (4 cyl) to Autozone for CEL check. Their
> rudimentary device gave this code and message:
>
> Code 0420: The PCM has determined that the catalyst system efficiency for
> bank 1 is below threshold for the current engine operating conditions.
>
> I suspect front O2 sensor based on some research I've done on the web.
Any
> ideas, other than paying the dealer $75 for the full diagnosis?
>
> Thanks...TH
>
Be advised the warranty for cat converters is a federal mandate in USA of 8
years or 80,000 miles. This also happens to be about the mileage that they
tend to die...

The rear 02 sensor (only one bank on a 4cyl) is actualy the one that
measures cat efficiency. Most common cause of this code is a dead cat.

Peace.

#3 (**permalink**) 01 Nov 2003, 10:03 am

"psychicmechanic" <psychicmechanic@hotmail.com> wrote in message
news

fydnQ29L6uR1j6iRVn-iQ@comcast.com...
>
> "Strorg" <strorg@strorg.org> wrote in message
> news

b6dnSmMk5S9Qj-iRVn-gg@comcast.com...
> > Took daughter's 99 Accord LX (4 cyl) to Autozone for CEL check. Their
> > rudimentary device gave this code and message:
> >
> > Code 0420: The PCM has determined that the catalyst system efficiency
for
> > bank 1 is below threshold for the current engine operating conditions.
> >
> > I suspect front O2 sensor based on some research I've done on the web.
> Any
> > ideas, other than paying the dealer $75 for the full diagnosis?
> >
> > Thanks...TH
> >
> Be advised the warranty for cat converters is a federal mandate in USA of
8
> years or 80,000 miles. This also happens to be about the mileage that they
> tend to die...
>
> The rear 02 sensor (only one bank on a 4cyl) is actualy the one that
> measures cat efficiency. Most common cause of this code is a dead cat.
>
> Peace.
>
>

Figures....just broke 80K miles.

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