P0420 - Catalytic Converter and 02 Sensors - Honda Accord

Hi..

I have a 1998 honda accord V6. I got the Check engine light today,
using an OBD scanner i found out the code was "P0420 - Catalytic
emission low on Bank #1". The local repair shop tell me that i need to
get the Catalytic convertor and the 02 sensors replaced.

I have the following questions for the group.
1. Does the code P0420 mean that the catalytic convertor is bad?
2. He quoted the cost for a replacement Catalytic convertor for $550
and O2 sensor for $138.. do these seem high?

Just a few days back i had replaced the alternator in this car .. FYI..

Thanks,
Ritesh

wrote:
>
> Hi..
>
> I have a 1998 honda accord V6. I got the Check engine light today,
> using an OBD scanner i found out the code was "P0420 - Catalytic
> emission low on Bank #1". The local repair shop tell me that i need to
> get the Catalytic convertor and the 02 sensors replaced.
>
> I have the following questions for the group.
> 1. Does the code P0420 mean that the catalytic convertor is bad?
> 2. He quoted the cost for a replacement Catalytic convertor for $550
> and O2 sensor for $138.. do these seem high?
>
> Just a few days back i had replaced the alternator in this car .. FYI..
>
> Thanks,
> Ritesh
--------------------------------------

"Catalyst system efficiency below threshold" is the interpretation. Your
second O2 sensor says that the CAT isn't scrubbing enough stuff from the
exhaust. It MIGHT just be the second O2 sensor's fault. (have you ever
had 'poor starting' after sitting overnight / weekend?) Maybe you've
never cleaned your injectors and so you've got a damaged CAT on that
side. Maybe you've used too many additives and have a damaged CAT. More
likely the former.

If it was mine, I'd do a tune -up, reset the code, put a can of techron
into a full tank and drive it until it was almost empty, preferably on a
long, fast highway drive on a hot day. The prices quoted are good to
low, as long as the O2 sensor is a real NGK. If it's Bosch, tell him to
get you a REAL sensor. Was he going to replace the first or second
sensor, BTW.??

'Curly'

On 29 Mar 2006 16:48:25 -0800, wrote:

>Hi..
>
>I have a 1998 honda accord V6. I got the Check engine light today,
>using an OBD scanner i found out the code was "P0420 - Catalytic
>emission low on Bank #1". The local repair shop tell me that i need to
>get the Catalytic convertor and the 02 sensors replaced.
>
>I have the following questions for the group.
>1. Does the code P0420 mean that the catalytic convertor is bad?
>2. He quoted the cost for a replacement Catalytic convertor for $550
>and O2 sensor for $138.. do these seem high?
>
>Just a few days back i had replaced the alternator in this car .. FYI..
>
>Thanks,
>Ritesh
it just needs a cat, no o2 sensor.
Chip

wrote:
> Hi..
>
> I have a 1998 honda accord V6. I got the Check engine light today,
> using an OBD scanner i found out the code was "P0420 - Catalytic
> emission low on Bank #1". The local repair shop tell me that i need to
> get the Catalytic convertor and the 02 sensors replaced.
>
> I have the following questions for the group.
> 1. Does the code P0420 mean that the catalytic convertor is bad?
> 2. He quoted the cost for a replacement Catalytic convertor for $550
> and O2 sensor for $138.. do these seem high?
>
> Just a few days back i had replaced the alternator in this car .. FYI..

id replace the O2 sensor, but NOT the cat. cats just dont go bad that
quickly unless youre using gas from questionable sources. for $138 it
sounds like theyre using a generic sensor. an OEM one would be closer to
$200 for the sensor alone.

Majestic prices out to $99 for the sensor (plus shipping and handling).
That would probably be NGK. Yeah, the prices are otherwise good. Did he
say the brand of cat it was? A DEC?

Do get a tuneup. Cat's don't go bad by themselves, something else cause
them to go bad.

As far as Bosch goes, they are fine sensors and they are the most
installed sensors on the road. NGK and Denso only make sensors under
Bosch licenses.

wrote in
ups.com:

> Hi..
>
> I have a 1998 honda accord V6. I got the Check engine light today,
> using an OBD scanner i found out the code was "P0420 - Catalytic
> emission low on Bank #1". The local repair shop tell me that i need to
> get the Catalytic convertor and the 02 sensors replaced.
>
> I have the following questions for the group.
> 1. Does the code P0420 mean that the catalytic convertor is bad?
> 2. He quoted the cost for a replacement Catalytic convertor for $550
> and O2 sensor for $138.. do these seem high?
>
> Just a few days back i had replaced the alternator in this car .. FYI..
>



There have been reports of this being caused by a cracked exhaust manifold.
The crack is just below the primary oxygen sensor, and allows air in AFTER
the sensor, which the primary sensor cannot detect.

Check for that before needlessly replacing the cat.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

> wrote
> As far as Bosch goes, they are fine sensors and they are
> the most
> installed sensors on the road.

They are not Honda OEM, though, and anecdotal reports here
indicate they are a roll of the dice compared to OEM.

> NGK and Denso only make sensors under
> Bosch licenses.

What does this mean? That a Denso O2 sensor is identical to
a Bosch O2 sensor, for the same car model and year?

I don't think so.

Another online parts resource for the OP:
https://www.automedicsupply.com/

About $70 for the upstream O2 sensor (OEM, Denso).
Another $70 for the downstream O2 sensor (OEM, Denso).

On 30 Mar 2006 07:46:50 GMT, "TeGGeR®" > wrote:

wrote in
oups.com:
>
>> Hi..
>>
>> I have a 1998 honda accord V6. I got the Check engine light today,
>> using an OBD scanner i found out the code was "P0420 - Catalytic
>> emission low on Bank #1". The local repair shop tell me that i need to
>> get the Catalytic convertor and the 02 sensors replaced.
>>
>> I have the following questions for the group.
>> 1. Does the code P0420 mean that the catalytic convertor is bad?
>> 2. He quoted the cost for a replacement Catalytic convertor for $550
>> and O2 sensor for $138.. do these seem high?
>>
>> Just a few days back i had replaced the alternator in this car .. FYI..
>>
>
>
>
>There have been reports of this being caused by a cracked exhaust manifold.
>The crack is just below the primary oxygen sensor, and allows air in AFTER
>the sensor, which the primary sensor cannot detect.
>
>Check for that before needlessly replacing the cat.


accord cats go bad all the time in from 98 to 02. It's very common
after 80,000 miles.
Chip

chip > wrote in
:

> On 30 Mar 2006 07:46:50 GMT, "TeGGeR®" > wrote:
>
wrote in
roups.com:
>>
>>> Hi..
>>>
>>> I have a 1998 honda accord V6. I got the Check engine light today,
>>> using an OBD scanner i found out the code was "P0420 - Catalytic
>>> emission low on Bank #1". The local repair shop tell me that i need
>>> to get the Catalytic convertor and the 02 sensors replaced.
>>>
>>> I have the following questions for the group.
>>> 1. Does the code P0420 mean that the catalytic convertor is bad?
>>> 2. He quoted the cost for a replacement Catalytic convertor for $550
>>> and O2 sensor for $138.. do these seem high?
>>>
>>> Just a few days back i had replaced the alternator in this car ..
>>> FYI..
>>>
>>
>>
>>
>>There have been reports of this being caused by a cracked exhaust
>>manifold. The crack is just below the primary oxygen sensor, and
>>allows air in AFTER the sensor, which the primary sensor cannot
>>detect.
>>
>>Check for that before needlessly replacing the cat.
>
>
> accord cats go bad all the time in from 98 to 02. It's very common
> after 80,000 miles.


Did you know that American Honda has recently agreed to warranty certain
cats for 14 years and 150,000 miles? This exceeds the Federally mandated
8/80 warranty.


--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

I have a 1998 EX V6 coupe and just installed the Honda OEM fog lights.
They work fine but I have some questions/observations:

1) They only operate when the headlights are turned on...not with the
parking lights alone or no lights...headlights MUST be on.

2) They continue to stay on when switching to high beams. Never
noticed this on other cars. Always seemed that fog lights cut out for
high beam operation.

Is all of this normal? Thanks.

KL