Re: 98 Accord Ex running rich
 

P0420 is typically associated with a Three Way Catalytic
Converter failure or with some type of exhaust leak. First,
was that the only error code? IOW did they also forget to
look for other error codes?

A late model vehicle should not be suffering such failures.
IOW reasons for such failures should also be addressed. How
was gas mileage before these failures were happening? Engine
problem that was dumping too much gasoline into the exhaust
system would then degrade the converter. After all, what does
a converter do? Burn the gasoline that the engine did not.
For example, if gas mileage has always been low (ie low 20s
MPG), then that problem may be why a converter failed.

This is why you have a good dealer. Service mechanics will
have enough experience with these rare failures as to quickly
identify the problem AND locate the reason why that failure
occurred. Because the Autozone man could not tell you this
simple information up front, then assume he is not good enough
to perform any service.

Assume there is something else wrong since a catalytic
converter failure alone just should not occur. Something else
should have contributed to that failure. Too much gasoline
not burned in the engine is bad for converters.

electricked wrote:
> I posted earlier with some questions regarding the check enging
> light that came on few days ago. I put about 5 gallons of gas on
> my last stop and it drove about 90 miles which is terrible. Less
> than 20 miles a gallon. Terrible! Anyway, today I went to AutoZone
> to get the free scan code check and it turned up P0420. Does
> anyone know what this code means? The guy at AutoZone said it
> might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running
> rich for the past week, and especially noticable in the last
> couple of days. The check engine light was reseted today when he
> tested it, and it hasn't come on since then. After he checked it,
> it's been running smooth. No hesitation, seems it's not running
> rich anymore, but only time will tell. I'll keep observing for
> the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.

Re: 98 Accord Ex running rich
 

P0420 is typically associated with a Three Way Catalytic
Converter failure or with some type of exhaust leak. First,
was that the only error code? IOW did they also forget to
look for other error codes?

A late model vehicle should not be suffering such failures.
IOW reasons for such failures should also be addressed. How
was gas mileage before these failures were happening? Engine
problem that was dumping too much gasoline into the exhaust
system would then degrade the converter. After all, what does
a converter do? Burn the gasoline that the engine did not.
For example, if gas mileage has always been low (ie low 20s
MPG), then that problem may be why a converter failed.

This is why you have a good dealer. Service mechanics will
have enough experience with these rare failures as to quickly
identify the problem AND locate the reason why that failure
occurred. Because the Autozone man could not tell you this
simple information up front, then assume he is not good enough
to perform any service.

Assume there is something else wrong since a catalytic
converter failure alone just should not occur. Something else
should have contributed to that failure. Too much gasoline
not burned in the engine is bad for converters.

electricked wrote:
> I posted earlier with some questions regarding the check enging
> light that came on few days ago. I put about 5 gallons of gas on
> my last stop and it drove about 90 miles which is terrible. Less
> than 20 miles a gallon. Terrible! Anyway, today I went to AutoZone
> to get the free scan code check and it turned up P0420. Does
> anyone know what this code means? The guy at AutoZone said it
> might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running
> rich for the past week, and especially noticable in the last
> couple of days. The check engine light was reseted today when he
> tested it, and it hasn't come on since then. After he checked it,
> it's been running smooth. No hesitation, seems it's not running
> rich anymore, but only time will tell. I'll keep observing for
> the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.

Re: 98 Accord Ex running rich
 

P0420 is typically associated with a Three Way Catalytic
Converter failure or with some type of exhaust leak. First,
was that the only error code? IOW did they also forget to
look for other error codes?

A late model vehicle should not be suffering such failures.
IOW reasons for such failures should also be addressed. How
was gas mileage before these failures were happening? Engine
problem that was dumping too much gasoline into the exhaust
system would then degrade the converter. After all, what does
a converter do? Burn the gasoline that the engine did not.
For example, if gas mileage has always been low (ie low 20s
MPG), then that problem may be why a converter failed.

This is why you have a good dealer. Service mechanics will
have enough experience with these rare failures as to quickly
identify the problem AND locate the reason why that failure
occurred. Because the Autozone man could not tell you this
simple information up front, then assume he is not good enough
to perform any service.

Assume there is something else wrong since a catalytic
converter failure alone just should not occur. Something else
should have contributed to that failure. Too much gasoline
not burned in the engine is bad for converters.

electricked wrote:
> I posted earlier with some questions regarding the check enging
> light that came on few days ago. I put about 5 gallons of gas on
> my last stop and it drove about 90 miles which is terrible. Less
> than 20 miles a gallon. Terrible! Anyway, today I went to AutoZone
> to get the free scan code check and it turned up P0420. Does
> anyone know what this code means? The guy at AutoZone said it
> might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running
> rich for the past week, and especially noticable in the last
> couple of days. The check engine light was reseted today when he
> tested it, and it hasn't come on since then. After he checked it,
> it's been running smooth. No hesitation, seems it's not running
> rich anymore, but only time will tell. I'll keep observing for
> the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.

Re: 98 Accord Ex running rich
 

P0420 is typically associated with a Three Way Catalytic
Converter failure or with some type of exhaust leak. First,
was that the only error code? IOW did they also forget to
look for other error codes?

A late model vehicle should not be suffering such failures.
IOW reasons for such failures should also be addressed. How
was gas mileage before these failures were happening? Engine
problem that was dumping too much gasoline into the exhaust
system would then degrade the converter. After all, what does
a converter do? Burn the gasoline that the engine did not.
For example, if gas mileage has always been low (ie low 20s
MPG), then that problem may be why a converter failed.

This is why you have a good dealer. Service mechanics will
have enough experience with these rare failures as to quickly
identify the problem AND locate the reason why that failure
occurred. Because the Autozone man could not tell you this
simple information up front, then assume he is not good enough
to perform any service.

Assume there is something else wrong since a catalytic
converter failure alone just should not occur. Something else
should have contributed to that failure. Too much gasoline
not burned in the engine is bad for converters.

electricked wrote:
> I posted earlier with some questions regarding the check enging
> light that came on few days ago. I put about 5 gallons of gas on
> my last stop and it drove about 90 miles which is terrible. Less
> than 20 miles a gallon. Terrible! Anyway, today I went to AutoZone
> to get the free scan code check and it turned up P0420. Does
> anyone know what this code means? The guy at AutoZone said it
> might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running
> rich for the past week, and especially noticable in the last
> couple of days. The check engine light was reseted today when he
> tested it, and it hasn't come on since then. After he checked it,
> it's been running smooth. No hesitation, seems it's not running
> rich anymore, but only time will tell. I'll keep observing for
> the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.

98 Accord Ex running rich
 

Hello all,

I posted earlier with some questions regarding the check enging light that
came on few days ago. I put about 5 gallons of gas on my last stop and it
drove about 90 miles which is terrible. Less than 20 miles a gallon.
Terrible! Anyway, today I went to AutoZone to get the free scan code check
and it turned up P0420. Does anyone know what this code means? The guy at
AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
sensor or the catalytic converter since the car has been running rich for
the past week, and especially noticable in the last couple of days. The
check engine light was reseted today when he tested it, and it hasn't come
on since then. After he checked it, it's been running smooth. No hesitation,
seems it's not running rich anymore, but only time will tell. I'll keep
observing for the next few days and fix whatever needs to be fixed over the
weekend.

Any and all help is welcome and strongly appreciated.

Thank you!

--Viktor

Re: 98 Accord Ex running rich
 

In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
<welcomehowcome@hotmail.com> wrote:

> Hello all,
>
> I posted earlier with some questions regarding the check enging light that
> came on few days ago. I put about 5 gallons of gas on my last stop and it
> drove about 90 miles which is terrible. Less than 20 miles a gallon.
> Terrible! Anyway, today I went to AutoZone to get the free scan code check
> and it turned up P0420. Does anyone know what this code means? The guy at
> AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running rich for
> the past week, and especially noticable in the last couple of days. The
> check engine light was reseted today when he tested it, and it hasn't come
> on since then. After he checked it, it's been running smooth. No hesitation,
> seems it's not running rich anymore, but only time will tell. I'll keep
> observing for the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.
>
> Thank you!
>
> --Viktor

According to my manual--PO420-- shows up as
"Catalyst system efficiency below threshold."
I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
<welcomehowcome@hotmail.com> wrote:

> Hello all,
>
> I posted earlier with some questions regarding the check enging light that
> came on few days ago. I put about 5 gallons of gas on my last stop and it
> drove about 90 miles which is terrible. Less than 20 miles a gallon.
> Terrible! Anyway, today I went to AutoZone to get the free scan code check
> and it turned up P0420. Does anyone know what this code means? The guy at
> AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running rich for
> the past week, and especially noticable in the last couple of days. The
> check engine light was reseted today when he tested it, and it hasn't come
> on since then. After he checked it, it's been running smooth. No hesitation,
> seems it's not running rich anymore, but only time will tell. I'll keep
> observing for the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.
>
> Thank you!
>
> --Viktor

According to my manual--PO420-- shows up as
"Catalyst system efficiency below threshold."
I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
<welcomehowcome@hotmail.com> wrote:

> Hello all,
>
> I posted earlier with some questions regarding the check enging light that
> came on few days ago. I put about 5 gallons of gas on my last stop and it
> drove about 90 miles which is terrible. Less than 20 miles a gallon.
> Terrible! Anyway, today I went to AutoZone to get the free scan code check
> and it turned up P0420. Does anyone know what this code means? The guy at
> AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running rich for
> the past week, and especially noticable in the last couple of days. The
> check engine light was reseted today when he tested it, and it hasn't come
> on since then. After he checked it, it's been running smooth. No hesitation,
> seems it's not running rich anymore, but only time will tell. I'll keep
> observing for the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.
>
> Thank you!
>
> --Viktor

According to my manual--PO420-- shows up as
"Catalyst system efficiency below threshold."
I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
<welcomehowcome@hotmail.com> wrote:

> Hello all,
>
> I posted earlier with some questions regarding the check enging light that
> came on few days ago. I put about 5 gallons of gas on my last stop and it
> drove about 90 miles which is terrible. Less than 20 miles a gallon.
> Terrible! Anyway, today I went to AutoZone to get the free scan code check
> and it turned up P0420. Does anyone know what this code means? The guy at
> AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> sensor or the catalytic converter since the car has been running rich for
> the past week, and especially noticable in the last couple of days. The
> check engine light was reseted today when he tested it, and it hasn't come
> on since then. After he checked it, it's been running smooth. No hesitation,
> seems it's not running rich anymore, but only time will tell. I'll keep
> observing for the next few days and fix whatever needs to be fixed over the
> weekend.
>
> Any and all help is welcome and strongly appreciated.
>
> Thank you!
>
> --Viktor

According to my manual--PO420-- shows up as
"Catalyst system efficiency below threshold."
I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

yea, it means the 02 sensor after the cat indicates that the mixture is too
fuel-rich.... either the 2nd heater 02 circuit is malfunctioning, or (as it
has been mentionned here), the catalytic converter is failing... in wich
case it sucks to be you cuz thats one expensive replacement.

Get a real mechanic to check it out, if it's just the sensor, those should
go for under 80$ (i'm talking about the 2nd O2 sensor, not the first one
located on top of the cat).
It takes about 2 mins to install one, but you need to warm up the engine
first a bit, since the catalytic converter expands when warm and makes
installation easier.

If you need to replace the converter, thats anywhere from 170 - 400 $ right
there, depending on the model ....

These are, of course, prices for OEM or good brands ....
Bosch, etc...

ANd you're right, if the code is lit - this indicates to the ECU that there
is a malfunciton with the censor, which in turn disables the real-time fuel
control... which is made to allow for optimum fuel /air ratio (something
that the 02 sensor monitors).

In case of trouble, the car runs in open-loop mode, i.e. it reads data from
fuel injection tables... regardless of weither it makes for a healthy
fuel/air mixture... thus your car is "running rich".

Hope any of this was helpful

peace out





"T. Nelson" <tnelson@nospam.com> wrote in message
news:tnelson-0902041644390001@pm1-broad-102.snlo.dialup.fix.net...
> In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
> <welcomehowcome@hotmail.com> wrote:
>
> > Hello all,
> >
> > I posted earlier with some questions regarding the check enging light
that
> > came on few days ago. I put about 5 gallons of gas on my last stop and
it
> > drove about 90 miles which is terrible. Less than 20 miles a gallon.
> > Terrible! Anyway, today I went to AutoZone to get the free scan code
check
> > and it turned up P0420. Does anyone know what this code means? The guy
at
> > AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> > sensor or the catalytic converter since the car has been running rich
for
> > the past week, and especially noticable in the last couple of days. The
> > check engine light was reseted today when he tested it, and it hasn't
come
> > on since then. After he checked it, it's been running smooth. No
hesitation,
> > seems it's not running rich anymore, but only time will tell. I'll keep
> > observing for the next few days and fix whatever needs to be fixed over
the
> > weekend.
> >
> > Any and all help is welcome and strongly appreciated.
> >
> > Thank you!
> >
> > --Viktor
>
> According to my manual--PO420-- shows up as
> "Catalyst system efficiency below threshold."
> I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

yea, it means the 02 sensor after the cat indicates that the mixture is too
fuel-rich.... either the 2nd heater 02 circuit is malfunctioning, or (as it
has been mentionned here), the catalytic converter is failing... in wich
case it sucks to be you cuz thats one expensive replacement.

Get a real mechanic to check it out, if it's just the sensor, those should
go for under 80$ (i'm talking about the 2nd O2 sensor, not the first one
located on top of the cat).
It takes about 2 mins to install one, but you need to warm up the engine
first a bit, since the catalytic converter expands when warm and makes
installation easier.

If you need to replace the converter, thats anywhere from 170 - 400 $ right
there, depending on the model ....

These are, of course, prices for OEM or good brands ....
Bosch, etc...

ANd you're right, if the code is lit - this indicates to the ECU that there
is a malfunciton with the censor, which in turn disables the real-time fuel
control... which is made to allow for optimum fuel /air ratio (something
that the 02 sensor monitors).

In case of trouble, the car runs in open-loop mode, i.e. it reads data from
fuel injection tables... regardless of weither it makes for a healthy
fuel/air mixture... thus your car is "running rich".

Hope any of this was helpful

peace out





"T. Nelson" <tnelson@nospam.com> wrote in message
news:tnelson-0902041644390001@pm1-broad-102.snlo.dialup.fix.net...
> In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
> <welcomehowcome@hotmail.com> wrote:
>
> > Hello all,
> >
> > I posted earlier with some questions regarding the check enging light
that
> > came on few days ago. I put about 5 gallons of gas on my last stop and
it
> > drove about 90 miles which is terrible. Less than 20 miles a gallon.
> > Terrible! Anyway, today I went to AutoZone to get the free scan code
check
> > and it turned up P0420. Does anyone know what this code means? The guy
at
> > AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> > sensor or the catalytic converter since the car has been running rich
for
> > the past week, and especially noticable in the last couple of days. The
> > check engine light was reseted today when he tested it, and it hasn't
come
> > on since then. After he checked it, it's been running smooth. No
hesitation,
> > seems it's not running rich anymore, but only time will tell. I'll keep
> > observing for the next few days and fix whatever needs to be fixed over
the
> > weekend.
> >
> > Any and all help is welcome and strongly appreciated.
> >
> > Thank you!
> >
> > --Viktor
>
> According to my manual--PO420-- shows up as
> "Catalyst system efficiency below threshold."
> I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

yea, it means the 02 sensor after the cat indicates that the mixture is too
fuel-rich.... either the 2nd heater 02 circuit is malfunctioning, or (as it
has been mentionned here), the catalytic converter is failing... in wich
case it sucks to be you cuz thats one expensive replacement.

Get a real mechanic to check it out, if it's just the sensor, those should
go for under 80$ (i'm talking about the 2nd O2 sensor, not the first one
located on top of the cat).
It takes about 2 mins to install one, but you need to warm up the engine
first a bit, since the catalytic converter expands when warm and makes
installation easier.

If you need to replace the converter, thats anywhere from 170 - 400 $ right
there, depending on the model ....

These are, of course, prices for OEM or good brands ....
Bosch, etc...

ANd you're right, if the code is lit - this indicates to the ECU that there
is a malfunciton with the censor, which in turn disables the real-time fuel
control... which is made to allow for optimum fuel /air ratio (something
that the 02 sensor monitors).

In case of trouble, the car runs in open-loop mode, i.e. it reads data from
fuel injection tables... regardless of weither it makes for a healthy
fuel/air mixture... thus your car is "running rich".

Hope any of this was helpful

peace out





"T. Nelson" <tnelson@nospam.com> wrote in message
news:tnelson-0902041644390001@pm1-broad-102.snlo.dialup.fix.net...
> In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
> <welcomehowcome@hotmail.com> wrote:
>
> > Hello all,
> >
> > I posted earlier with some questions regarding the check enging light
that
> > came on few days ago. I put about 5 gallons of gas on my last stop and
it
> > drove about 90 miles which is terrible. Less than 20 miles a gallon.
> > Terrible! Anyway, today I went to AutoZone to get the free scan code
check
> > and it turned up P0420. Does anyone know what this code means? The guy
at
> > AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> > sensor or the catalytic converter since the car has been running rich
for
> > the past week, and especially noticable in the last couple of days. The
> > check engine light was reseted today when he tested it, and it hasn't
come
> > on since then. After he checked it, it's been running smooth. No
hesitation,
> > seems it's not running rich anymore, but only time will tell. I'll keep
> > observing for the next few days and fix whatever needs to be fixed over
the
> > weekend.
> >
> > Any and all help is welcome and strongly appreciated.
> >
> > Thank you!
> >
> > --Viktor
>
> According to my manual--PO420-- shows up as
> "Catalyst system efficiency below threshold."
> I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

yea, it means the 02 sensor after the cat indicates that the mixture is too
fuel-rich.... either the 2nd heater 02 circuit is malfunctioning, or (as it
has been mentionned here), the catalytic converter is failing... in wich
case it sucks to be you cuz thats one expensive replacement.

Get a real mechanic to check it out, if it's just the sensor, those should
go for under 80$ (i'm talking about the 2nd O2 sensor, not the first one
located on top of the cat).
It takes about 2 mins to install one, but you need to warm up the engine
first a bit, since the catalytic converter expands when warm and makes
installation easier.

If you need to replace the converter, thats anywhere from 170 - 400 $ right
there, depending on the model ....

These are, of course, prices for OEM or good brands ....
Bosch, etc...

ANd you're right, if the code is lit - this indicates to the ECU that there
is a malfunciton with the censor, which in turn disables the real-time fuel
control... which is made to allow for optimum fuel /air ratio (something
that the 02 sensor monitors).

In case of trouble, the car runs in open-loop mode, i.e. it reads data from
fuel injection tables... regardless of weither it makes for a healthy
fuel/air mixture... thus your car is "running rich".

Hope any of this was helpful

peace out





"T. Nelson" <tnelson@nospam.com> wrote in message
news:tnelson-0902041644390001@pm1-broad-102.snlo.dialup.fix.net...
> In article <eaSdna0OT-5qlrXdRVn-hg@comcast.com>, "electricked"
> <welcomehowcome@hotmail.com> wrote:
>
> > Hello all,
> >
> > I posted earlier with some questions regarding the check enging light
that
> > came on few days ago. I put about 5 gallons of gas on my last stop and
it
> > drove about 90 miles which is terrible. Less than 20 miles a gallon.
> > Terrible! Anyway, today I went to AutoZone to get the free scan code
check
> > and it turned up P0420. Does anyone know what this code means? The guy
at
> > AutoZone said it might be the O2 sensor. I'm thinking it's either the O2
> > sensor or the catalytic converter since the car has been running rich
for
> > the past week, and especially noticable in the last couple of days. The
> > check engine light was reseted today when he tested it, and it hasn't
come
> > on since then. After he checked it, it's been running smooth. No
hesitation,
> > seems it's not running rich anymore, but only time will tell. I'll keep
> > observing for the next few days and fix whatever needs to be fixed over
the
> > weekend.
> >
> > Any and all help is welcome and strongly appreciated.
> >
> > Thank you!
> >
> > --Viktor
>
> According to my manual--PO420-- shows up as
> "Catalyst system efficiency below threshold."
> I don't know what this means--can anybody else interpret what this means?

Re: 98 Accord Ex running rich
 

Tom and Nelson, thanks for your speedy replies.

The gentleman at AutoZone tried looking for additional codes, but that's the
only one he got. The car is 6 years old, which is not exactly late model,
but I follow you on that one. It's got 99K miles on it. I ran in the mid
30's per gallon couple weeks back. Now it runs below 20. My understanding is
that cold air causes more gas to be burned due to more oxygen coming in
because of compression in cold weather conditions. The loss in gas economy
is usually 10% which is about 3-4miles per gallon, and I've lost 15 or so.
That's not normal.

If someone has any other suggestions, please speak up.

Thanks!

--Viktor

"w_tom" <w_tom1@hotmail.com> wrote in message
news:40281356.BF019CC2@hotmail.com...
> P0420 is typically associated with a Three Way Catalytic
> Converter failure or with some type of exhaust leak. First,
> was that the only error code? IOW did they also forget to
> look for other error codes?
>
> A late model vehicle should not be suffering such failures.
> IOW reasons for such failures should also be addressed. How
> was gas mileage before these failures were happening? Engine
> problem that was dumping too much gasoline into the exhaust
> system would then degrade the converter. After all, what does
> a converter do? Burn the gasoline that the engine did not.
> For example, if gas mileage has always been low (ie low 20s
> MPG), then that problem may be why a converter failed.
>
> This is why you have a good dealer. Service mechanics will
> have enough experience with these rare failures as to quickly
> identify the problem AND locate the reason why that failure
> occurred. Because the Autozone man could not tell you this
> simple information up front, then assume he is not good enough
> to perform any service.
>
> Assume there is something else wrong since a catalytic
> converter failure alone just should not occur. Something else
> should have contributed to that failure. Too much gasoline
> not burned in the engine is bad for converters.
>
> electricked wrote:
> > I posted earlier with some questions regarding the check enging
> > light that came on few days ago. I put about 5 gallons of gas on
> > my last stop and it drove about 90 miles which is terrible. Less
> > than 20 miles a gallon. Terrible! Anyway, today I went to AutoZone
> > to get the free scan code check and it turned up P0420. Does
> > anyone know what this code means? The guy at AutoZone said it
> > might be the O2 sensor. I'm thinking it's either the O2
> > sensor or the catalytic converter since the car has been running
> > rich for the past week, and especially noticable in the last
> > couple of days. The check engine light was reseted today when he
> > tested it, and it hasn't come on since then. After he checked it,
> > it's been running smooth. No hesitation, seems it's not running
> > rich anymore, but only time will tell. I'll keep observing for
> > the next few days and fix whatever needs to be fixed over the
> > weekend.
> >
> > Any and all help is welcome and strongly appreciated.

Re: 98 Accord Ex running rich
 

Tom and Nelson, thanks for your speedy replies.

The gentleman at AutoZone tried looking for additional codes, but that's the
only one he got. The car is 6 years old, which is not exactly late model,
but I follow you on that one. It's got 99K miles on it. I ran in the mid
30's per gallon couple weeks back. Now it runs below 20. My understanding is
that cold air causes more gas to be burned due to more oxygen coming in
because of compression in cold weather conditions. The loss in gas economy
is usually 10% which is about 3-4miles per gallon, and I've lost 15 or so.
That's not normal.

If someone has any other suggestions, please speak up.

Thanks!

--Viktor

"w_tom" <w_tom1@hotmail.com> wrote in message
news:40281356.BF019CC2@hotmail.com...
> P0420 is typically associated with a Three Way Catalytic
> Converter failure or with some type of exhaust leak. First,
> was that the only error code? IOW did they also forget to
> look for other error codes?
>
> A late model vehicle should not be suffering such failures.
> IOW reasons for such failures should also be addressed. How
> was gas mileage before these failures were happening? Engine
> problem that was dumping too much gasoline into the exhaust
> system would then degrade the converter. After all, what does
> a converter do? Burn the gasoline that the engine did not.
> For example, if gas mileage has always been low (ie low 20s
> MPG), then that problem may be why a converter failed.
>
> This is why you have a good dealer. Service mechanics will
> have enough experience with these rare failures as to quickly
> identify the problem AND locate the reason why that failure
> occurred. Because the Autozone man could not tell you this
> simple information up front, then assume he is not good enough
> to perform any service.
>
> Assume there is something else wrong since a catalytic
> converter failure alone just should not occur. Something else
> should have contributed to that failure. Too much gasoline
> not burned in the engine is bad for converters.
>
> electricked wrote:
> > I posted earlier with some questions regarding the check enging
> > light that came on few days ago. I put about 5 gallons of gas on
> > my last stop and it drove about 90 miles which is terrible. Less
> > than 20 miles a gallon. Terrible! Anyway, today I went to AutoZone
> > to get the free scan code check and it turned up P0420. Does
> > anyone know what this code means? The guy at AutoZone said it
> > might be the O2 sensor. I'm thinking it's either the O2
> > sensor or the catalytic converter since the car has been running
> > rich for the past week, and especially noticable in the last
> > couple of days. The check engine light was reseted today when he
> > tested it, and it hasn't come on since then. After he checked it,
> > it's been running smooth. No hesitation, seems it's not running
> > rich anymore, but only time will tell. I'll keep observing for
> > the next few days and fix whatever needs to be fixed over the
> > weekend.
> >
> > Any and all help is welcome and strongly appreciated.