Hey..thakns a lot for the info, its really appreciated. I have a 96
civic and my engine check light does come on. I have had the problem
identified by a mechanic...it seems that the valve itself is fine but
the electronic sensor attached to it has malfunctioned. So I was
wondering wether to get the whole thing replaced...is the engine check
light the only indicator that tells me if my EGR is working, or is
there some other way to monitor it?

 

Im out of town for a couple of days...will get the exact codes for you
once I get back. And as I said, appreciate all the advice..ur awesome!

 

So what I get from this is that if the exhaust
gases after the cat are too rich in O2, the post-
cat sensor will trim back the fuel mixture as
well. This means that the cat is not damaged
from the pre-cat sensor being unplugged, right?

t

 

Sorry, that link sucked. Go to Oxygensensors.com
and enter the make and model, and it shows a pic
of both the pre and post cat sensors.

t

 

r2000swler@hotmail.com wrote:

> Sorry about the quoting thing, I am posting directly via Google beta
> and it dosen't give you a lot of control. And qx.net, my ISP, only
> supports outlook.

I believe that only means that your ISP will assist its clients in using
only Outlook (Express), but no other newsreader programs. You should be
able to use any newsreader program with your ISP's news server.

 

Sorry about the quoting thing, I am posting directly via Google beta
and it dosen't give you a lot of control. And qx.net, my ISP, only
supports
outlook.

And sorry aboutmy confussion about pre and post O2 senosors.
I haven't had a car new enough to have a pre and post O2 sensor.

Terry

 

"disallow" <loewen_t at yahoo.ca @>> wrote in
news:91eaccac3f8fba64674e163cbef9651b@localhost.ta lkaboutautos.com:

First of all, I am posting about a Nissan in the Honda group, I know
I know.... but those guys over there are jerks and never respond, us
honda guys are much friendlier.... lol, and I have a 98 civic. I just
like helping people, and not everyone has the privelege to drive a
honda.... :)

>> so the only way to test if the cat is fried is
>> to do an emissions test?


>In a pre-OBD-II car (with no downstream O2 sensor), yes.

93 Altima has a downstream sensor. The downstream one has more than
1 wire too, the pre-cat one has only 1 wire (and thats the one i plugged
back in). You can get pics of either the pre or post cat on this
website:

http://tinyurl.com/5myvs

or

https://www.automedicsupply.com/cata...938447b18c929#

>> Wouldn't this cause
>> the ECU to throw a code and set off the CEL?


>Only in an OBD-II car. Unless the ECU receives an incorrect signal fom
>some
>sort of sensor, it has no way of knowing how good the cat is.

>The downstream sensor is supposed to flatline, showing a constant high
>voltage. As the cat starts to degrade over time, it leaves unconsumed
>oxygen in the exhaust. This oxygen will cause the downstream sensor's
>voltage to begin fluctuating. Once the fluctuations cross a certain
>threshhold, the MIL will illuminate. The MIL will also illuminate if >the

>downstream sensor itself malfunctions.


>> (cuz CEL never came on)
>>
>> Just wondering if there was a possible way we
>> might have been able to dodge the bullet of
>> cooking the catalyst....
>>


>If you don't have to pass an emissions test, the car runs OK, and no
>error
>codes are stored, then I wouldn't worry about it.

>If you do have to get the cat replaced, aftermarket ones are available
>for as little as $150 installed, depending on your region. Honda OEM
>cats are horrendously, shockingly expensive.

Since we are in Manitoba, no biggie, and I will probably leave it. But
if he ever moves to another province, ie BC or ONT, then we'll probably
have to address it then. Does Alberta have Clean Air legislation?


>--
>TeGGeR®

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

I found a Converter on Maximumautoparts.com for $135 US. Not to bad,
looks like it should be OK to install too, as long as I have access to
impact. but we will leave it for now, as long
as running with a possibly bad Cat does not
damage the engine.

Thanks Tegger, you are very helpful.

T

 

so the only way to test if the cat is fried is
to do an emissions test? Wouldn't this cause
the ECU to throw a code and set off the CEL?
(cuz CEL never came on)

Just wondering if there was a possible way we
might have been able to dodge the bullet of
cooking the catalyst....

t

 

What are the respective purposes of the pre and
post cat O2 Sensors? My little brothers pre cat
o2 sensor was unplugged on his 93 Nissan
Altima. How would this affect engine operation
and economy? (I did plug it back in, hopefully
it was unplugged for no good reason) (Also, it
only had 1 wire.)

Thanks
t

 

A bad/failing O2 sensor will cost you several MPG.
BTDT
And try passing a rigouris emission test without one.

The EGR is to manage NOX emmisions.
Terry

 

Sean Dinh wrote:
>
> EGR is only needed if your Honda is an automatic. Stick cars
> don't need it because they don't waste a lot of fuel running
> the transmission during idling.

Honda has used EGR valves on both automatics and stick shifts. The 1994
Civic VX manual had an EGR valve, the 1994 Civic EX Automatic did not.

 

contagiouss_blue wrote:
>
> Hey..thakns a lot for the info, its really appreciated. I have a 96
> civic and my engine check light does come on. I have had the problem
> identified by a mechanic...it seems that the valve itself is fine but
> the electronic sensor attached to it has malfunctioned. So I was
> wondering wether to get the whole thing replaced...is the engine check
> light the only indicator that tells me if my EGR is working, or is
> there some other way to monitor it?

Typically, the EGR valve is controlled closed-loop by the ECU. The ECU
applies a signal to the EGR valve and then reads the feedback from the
sensor to see how far open the valve is. The ECU then modifies the drive
signal until it reads back the correct valve-opening (for the current
operating conditions) from the sensor. So with a broken sensor, even
tough the valve can still open and close, the EGR system is not working
properly. Unlike the second O2 sensor, which only function is to turn on
the check engine light, the EGR valve sensor is part of the emissions
control loop.
--
================================================== =====
A very modest collection of Honda tech info can be found at:
http://www.geocities.com/ng_randolph

 

EGR is only needed if your Honda is an automatic. Stick cars
don't need it because they don't waste a lot of fuel running
the transmission during idling.

disallow wrote:
>
> my 98 civic (non vtec though) does not have an EGR valve.

 

my 98 civic (non vtec though) does not have an EGR valve.

 

Hi

I just wanted to know what exactly an EGR valve does, and if there is
one that is not working properly in a car, what damage is possible.
This is a civic engine...non VTEC. Anybody??

 

I have a 1992 Civic EX auto. Does it have an EGR valve, and where
approximately is it located. I have a shop manual for the car, but I
can not seem to find any reference to an EGR valve.

Thanks,

Jim

n Tue, 29 Mar 2005 21:58:09 UTC, Randolph <trash@junkmail.com> wrote:

>
> Sean Dinh wrote:
> >
> > EGR is only needed if your Honda is an automatic. Stick cars
> > don't need it because they don't waste a lot of fuel running
> > the transmission during idling.
>
> Honda has used EGR valves on both automatics and stick shifts. The 1994
> Civic VX manual had an EGR valve, the 1994 Civic EX Automatic did not.


--

 

"Jim Wilkerson" <wilkerj@attglobal.net> wrote in news:RFFxzJm83E64-pn2-
mKd0hnvlpPmb@localhost:

> I have a 1992 Civic EX auto. Does it have an EGR valve, and where
> approximately is it located. I have a shop manual for the car, but I
> can not seem to find any reference to an EGR valve.



If you have EGR, the valve is located just behind the valve cover, probably
on the passenger's (right) side of it.

The control box is on the right side of the firewall, next to the wiper
motor. If you just have a big open space on the firewall inboard of the
wiper motor, then you have no EGR.


--
TeGGeR®

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

 

Jim Wilkerson wrote:
>
> I have a 1992 Civic EX auto. Does it have an EGR valve, and where
> approximately is it located. I have a shop manual for the car, but I
> can not seem to find any reference to an EGR valve.

You have the D16Z6 engine, and it did not have an EGR valve regardless
of what transmission it was bolted to.

 

My car is having this similar problem. My car, once started and running cold, has a hard time idling. Normally, I idle at about 1K or less. When I start my car, it begins idling at 1,500 RPMs and slowly goes down, occasionally dying out. Sometimes, I can be stopped at a light or stop sign and when I gas it, my car dies. My mechanic is currently looking at the EGR valve, but I have replaced plugs and coil pack, what else could it be?

 

The EGR valve is Exhaust Gas Recirculation. One of the first pollution control devices, it helps control combustion temperature. Exhaust gases contain some fairly noxious Nitrogen compounds if the combustion temperature is too high. Early on it was found that just a little bit of exhaust gas fed back into the fuel/air mix lowers the combustion temperature, and reduces oxides of nitrogen, a major smog component.

The valve typically opens during moderate to high load, and closes under very light load or idle. If the valve is stuck open you may have a very uneven idle, or the car may die when you let off the gas. If it is stuck closed, the catalytic converter has to work harder and gets a bit hotter, shortening its life.