Honda Car Forum

Recently, on my 99 Civic EX I've replaced the exhaust from the
catylitic converter onward and also replaced all of the exhaust gaskets
and nuts/bolts, etc. During this unlikely hellish event I had to
resort to a hacksaw and a hammer to free several bolts, the worst of
which were the pre-cat. bolts. My engine light came on the next day.

As a consequence of my methods, I nicked one of the wires going to the
pre-cat O2 sensor, forgot to tape it up and drove for a couple weeks.
When re-fueling, I noticed my gas mileage dropped from 38mph to 22mph.
Thought it was a fluke, drove another week, filled up and calculated
the same milage. (Yeah, not too smart to drive it under these
conditions, but I had back problems that arose because I'd spent all of
a Saturday under the car trying to fix it, that prevented me from
getting under it again.)

I then patched up the wire (it was only a nick) and searched for any
other problems. Everything looked fine. I then reset the engine code
by unplugging the negative battery terminal.

Still same mileage and the light re-appeared. Now I assume, with all
that banging going on I probably ruined my pre-cat O2 sensor (It's 120K
old anyways). To be sure, I jumped the wire connections to read the
code and only got a
blink.............blink.............blink......etc ... I watched it
until it consistantly and equally until it blinked 65 times. No short
blinks, no fast ones, just a constantly slow blink every 3 seconds or
so.

What's this tell me?

P.S. I am aware that if it is the O2 sensor and I continue to run the
car this fuel rich I will plug the catylitic converter. I have been
trying to avoid driving the car since this problem has come about. I
just don't want to buy a $185 sensor until I'm damn sure.

Any ideas?,
John

John wrote:
>
> Recently, on my 99 Civic EX I've replaced the exhaust from the
> catylitic converter onward and also replaced all of the exhaust gaskets
> and nuts/bolts, etc. During this unlikely hellish event I had to
> resort to a hacksaw and a hammer to free several bolts, the worst of
> which were the pre-cat. bolts. My engine light came on the next day.
>
> As a consequence of my methods, I nicked one of the wires going to the
> pre-cat O2 sensor, forgot to tape it up and drove for a couple weeks.
> When re-fueling, I noticed my gas mileage dropped from 38mph to 22mph.
> Thought it was a fluke, drove another week, filled up and calculated
> the same milage. (Yeah, not too smart to drive it under these
> conditions, but I had back problems that arose because I'd spent all of
> a Saturday under the car trying to fix it, that prevented me from
> getting under it again.)
>
> I then patched up the wire (it was only a nick) and searched for any
> other problems. Everything looked fine. I then reset the engine code
> by unplugging the negative battery terminal.
>
> Still same mileage and the light re-appeared. Now I assume, with all
> that banging going on I probably ruined my pre-cat O2 sensor (It's 120K
> old anyways). To be sure, I jumped the wire connections to read the
> code and only got a
> blink.............blink.............blink......etc ... I watched it
> until it consistantly and equally until it blinked 65 times. No short
> blinks, no fast ones, just a constantly slow blink every 3 seconds or
> so.
>
> What's this tell me?
>
> P.S. I am aware that if it is the O2 sensor and I continue to run the
> car this fuel rich I will plug the catylitic converter. I have been
> trying to avoid driving the car since this problem has come about. I
> just don't want to buy a $185 sensor until I'm damn sure.
>
> Any ideas?,
> John
----------------------------------------

Too much banging could have trashed the CAT. It is made of GLASS, after
all. That's why it's wrapped in steel wool and asbestos inside to
protect it from shocks.

'Curly'

"John" <johnmcmurry@gmail.com> wrote in
news:1160673265.261802.200910@i3g2000cwc.googlegro ups.com:

<snip tale of woe>


>
> Still same mileage and the light re-appeared. Now I assume, with all
> that banging going on I probably ruined my pre-cat O2 sensor (It's
> 120K old anyways). To be sure, I jumped the wire connections to read
> the code and only got a
> blink.............blink.............blink......etc ... I watched it
> until it consistantly and equally until it blinked 65 times. No short
> blinks, no fast ones, just a constantly slow blink every 3 seconds or
> so.
>
> What's this tell me?



That's a code 1. Oxygen sensor.

However... The MIL flash code is ROUGH. to get the EXACT OBD-II code,
you need to have the code read with a proper OBD-II reader. The OBD code
consists of a letter and four numbers.

AutoZone or PartSource will read the code for free. Report it back here.



--
TeGGeR®

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

"'Curly Q. Links'" <motsco__@interbaun.com> wrote in
news:452EA4B4.67CB750E@interbaun.com:


>
> Too much banging could have trashed the CAT. It is made of GLASS,
> after all. That's why it's wrapped in steel wool and asbestos inside
> to protect it from shocks.
>


The core is actually made of alumina ceramic. It's pretty robust and will
tolerate a considerable amount of abuse. The exhaust pulses themselves are
very punishing to the cat.


--
TeGGeR®

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

TeGGeR® wrote:
> "'Curly Q. Links'" <motsco__@interbaun.com> wrote in
> news:452EA4B4.67CB750E@interbaun.com:
>
>
>
>>Too much banging could have trashed the CAT. It is made of GLASS,
>>after all. That's why it's wrapped in steel wool and asbestos inside
>>to protect it from shocks.
>>
>
>
>
> The core is actually made of alumina ceramic. It's pretty robust and will
> tolerate a considerable amount of abuse. The exhaust pulses themselves are
> very punishing to the cat.

Not to mention getting banged up against the occaisional corb or speed bump...
cats necessarily need to be pretty damn durable.

Matt Ion wrote:
> TeGGeR® wrote:
>
>> "'Curly Q. Links'" <motsco__@interbaun.com> wrote in
>> news:452EA4B4.67CB750E@interbaun.com:
>>
>>
>>> Too much banging could have trashed the CAT. It is made of GLASS,
>>> after all. That's why it's wrapped in steel wool and asbestos inside
>>> to protect it from shocks.
>>>
>>
>>
>>
>> The core is actually made of alumina ceramic. It's pretty robust and
>> will tolerate a considerable amount of abuse. The exhaust pulses
>> themselves are very punishing to the cat.
>
>
> Not to mention getting banged up against the occaisional corb or speed
> bump... cats necessarily need to be pretty damn durable.

Er... CURB.

Matt Ion <soundy106@gmail.com> wrote in
news:GIOXg.139060$R63.2310@pd7urf1no:

> Matt Ion wrote:
>> TeGGeR® wrote:
>>
>>> "'Curly Q. Links'" <motsco__@interbaun.com> wrote in
>>> news:452EA4B4.67CB750E@interbaun.com:
>>>
>>>
>>>> Too much banging could have trashed the CAT. It is made of GLASS,
>>>> after all. That's why it's wrapped in steel wool and asbestos
>>>> inside to protect it from shocks.
>>>>
>>>
>>>
>>>
>>> The core is actually made of alumina ceramic. It's pretty robust and
>>> will tolerate a considerable amount of abuse. The exhaust pulses
>>> themselves are very punishing to the cat.
>>
>>
>> Not to mention getting banged up against the occaisional corb or
>> speed bump... cats necessarily need to be pretty damn durable.
>
> Er... CURB.



Unless you're in jolly old Englend, in which case it's "kerb".

--
TeGGeR®

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

On Oct 12, 8:28 pm, "TeGGeR®" <teg...@tegger.c0m> wrote:
> "John" <johnmcmu...@gmail.com> wrote innews:1160673265.261802.200910@i3g2000cwc.googleg roups.com:
>
> <snip tale of woe>
>
>
>
> > Still same mileage and the light re-appeared. Now I assume, with all
> > that banging going on I probably ruined my pre-cat O2 sensor (It's
> > 120K old anyways). To be sure, I jumped the wire connections to read
> > the code and only got a
> > blink.............blink.............blink......etc ... I watched it
> > until it consistantly and equally until it blinked 65 times. No short
> > blinks, no fast ones, just a constantly slow blink every 3 seconds or
> > so.
>
> > What's this tell me?That's a code 1. Oxygen sensor.
>
> However... The MIL flash code is ROUGH. to get the EXACT OBD-II code,
> you need to have the code read with a proper OBD-II reader. The OBD code
> consists of a letter and four numbers.
>
> AutoZone or PartSource will read the code for free. Report it back here.
>
> --
> TeGGeR®
> \

Right you are. Advanced Auto Parts let me borrow their OBD-11 reader
and it reported a code:

P0131
O2 sensor
Circuit Low Volts
(Bank 1 Sensor 1)

Ordering a new primary sensor online today. Thanks.

John