Quick emissions question...
 

Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
ask because I have one here that just failed its California smog test due
to high NOx levels, which as I understand it is most commonly caused by an
EGR failure, but I can't seem to find an EGR system anywhere on the
engine. In fact I can't seem to find much of anything that can be tuned
or repaired to help this situation other than changing out the catalytic
converter, which I'm trying to avoid. The timing is supposedly
unchangeable (so says the Jeep service manual), and every other part
normally touched in an extensive tune up is brand new. New cooling system
components, too. If it's true that there is no EGR system that can be
checked, then I'm sort of left with the converter but I wanted to ask
first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

Exhaust Gas Recirculation is a part of the carburetor days, SMOG.
With your new cooling system you probably put too cold a thermostat
in, it should at least 195 degrees, and for this test I'd put in a 210
for the computer to lean out the mixture.
More than likely you need a new oxygen sensor.
And you need a new catalytic converter.
Then drive it for twenty minutes before the test so as the new
catalytic converter will reach sixteen hundred degree to do it's job and
chemically change pollutants like carbon monoxide (CO), hydrocarbons
(HC), oxides of Nitrogen (NOx) and particulate matter (PM) into harmless
substances like carbon dioxide (CO2), nitrogen (N2), and water vapor
(H2O):
http://www.tifac.org.in/do/hgt/case/convert.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

The Hurdy Gurdy Man wrote:
>
> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

Exhaust Gas Recirculation is a part of the carburetor days, SMOG.
With your new cooling system you probably put too cold a thermostat
in, it should at least 195 degrees, and for this test I'd put in a 210
for the computer to lean out the mixture.
More than likely you need a new oxygen sensor.
And you need a new catalytic converter.
Then drive it for twenty minutes before the test so as the new
catalytic converter will reach sixteen hundred degree to do it's job and
chemically change pollutants like carbon monoxide (CO), hydrocarbons
(HC), oxides of Nitrogen (NOx) and particulate matter (PM) into harmless
substances like carbon dioxide (CO2), nitrogen (N2), and water vapor
(H2O):
http://www.tifac.org.in/do/hgt/case/convert.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

The Hurdy Gurdy Man wrote:
>
> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

Exhaust Gas Recirculation is a part of the carburetor days, SMOG.
With your new cooling system you probably put too cold a thermostat
in, it should at least 195 degrees, and for this test I'd put in a 210
for the computer to lean out the mixture.
More than likely you need a new oxygen sensor.
And you need a new catalytic converter.
Then drive it for twenty minutes before the test so as the new
catalytic converter will reach sixteen hundred degree to do it's job and
chemically change pollutants like carbon monoxide (CO), hydrocarbons
(HC), oxides of Nitrogen (NOx) and particulate matter (PM) into harmless
substances like carbon dioxide (CO2), nitrogen (N2), and water vapor
(H2O):
http://www.tifac.org.in/do/hgt/case/convert.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

The Hurdy Gurdy Man wrote:
>
> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

Exhaust Gas Recirculation is a part of the carburetor days, SMOG.
With your new cooling system you probably put too cold a thermostat
in, it should at least 195 degrees, and for this test I'd put in a 210
for the computer to lean out the mixture.
More than likely you need a new oxygen sensor.
And you need a new catalytic converter.
Then drive it for twenty minutes before the test so as the new
catalytic converter will reach sixteen hundred degree to do it's job and
chemically change pollutants like carbon monoxide (CO), hydrocarbons
(HC), oxides of Nitrogen (NOx) and particulate matter (PM) into harmless
substances like carbon dioxide (CO2), nitrogen (N2), and water vapor
(H2O):
http://www.tifac.org.in/do/hgt/case/convert.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

The Hurdy Gurdy Man wrote:
>
> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

no egr and iwould look at the pcv hoses for dryrot and the cat. converter
could be busted up inside hit it a few times with you hand and see if it
rattles

The Hurdy Gurdy Man wrote:

> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

no egr and iwould look at the pcv hoses for dryrot and the cat. converter
could be busted up inside hit it a few times with you hand and see if it
rattles

The Hurdy Gurdy Man wrote:

> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

no egr and iwould look at the pcv hoses for dryrot and the cat. converter
could be busted up inside hit it a few times with you hand and see if it
rattles

The Hurdy Gurdy Man wrote:

> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

no egr and iwould look at the pcv hoses for dryrot and the cat. converter
could be busted up inside hit it a few times with you hand and see if it
rattles

The Hurdy Gurdy Man wrote:

> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!

Re: Quick emissions question...
 

A lean mixture aggravates a NOx concern. What Bill says carries some
weight, but you are probably looking to fatten it up, not lean it out more.
Vacuum leaks, bad O2, look for obvious things that are going to lean it out.
A fresh cat will make it pass, but be sure that you aren't just masking the
real problem, because it will fail again next year if you don't get to the
root of it.


Juice


"The Hurdy Gurdy Man" <bryan@linux.webicommerce.com> wrote in message
news:EQSzc.53068$TR1.51639@nwrddc01.gnilink.net...
>
> Did the 1994 Wrangler YJ 4.0L engine have an EGR system of any kind? I
> ask because I have one here that just failed its California smog test due
> to high NOx levels, which as I understand it is most commonly caused by an
> EGR failure, but I can't seem to find an EGR system anywhere on the
> engine. In fact I can't seem to find much of anything that can be tuned
> or repaired to help this situation other than changing out the catalytic
> converter, which I'm trying to avoid. The timing is supposedly
> unchangeable (so says the Jeep service manual), and every other part
> normally touched in an extensive tune up is brand new. New cooling system
> components, too. If it's true that there is no EGR system that can be
> checked, then I'm sort of left with the converter but I wanted to ask
> first to make sure I'm not overlooking something. Thanks!