FAILED CA. emissions; NOx too high. HELP please!

[snowwind1990]

"Bart" is running with SHOshop y-pipes....you should look up the invoices for July 1996 , Eugene or Eric Raborn....80MAF, programmed chip and UDPs(wonder where they went??)exhaust..etc...
for a 1991 Black.....now owned by me.
He proudly wears the SHOshop snorkel......see pic. in sig...
Am going to use 2 120z. bottles of methyl alcohol to 5 gals. 92 octane gas and drive him >55mph for about 15-20 mins...before the test..that should get him good and hot...hmm?

 

[srfdude]

SHO Boom:
srfdude, if your smog guy is that ****, amybe you should go to a gas station where they only do the sniffer test, if its clean it passes. them checking only makes them more money when they find something they can charge you to fix.

The sniffer is done on a dyno now; I know different areas of CA have different requirements. They got rid of all the mom and pop joints; everything is directly tied to the state computers. Progress? While all the smog from TJ comes blowing across the river, and cars from south of the border can cross, and do, by the thousands with all the smog stuff ripped off.
Mike

 

[Kevin Ryan]

The cat's controll NOX produced not the EGR. Your
cat's have lost there ability to change the CO2? to an inert gas. Bang the cat's. If you here ratteling the cat's have also started to break apart and will eventally pug the mufflers.
NOTE: Colorado's and California's IM240 tests are the same!!!

 

[shojuan]

Wrong. NOX are produced from high combustion temperatures. The ONLY purpose of EGR from an emmisions standpoint in to lower combustion temperatures to reduce oxides of nitrogen. I think you were thinking about CO not CO2 by the way. CO2 is the inert gas. CO is poison.

Rick

 

[Kevin Ryan]

Sorry, the way it goes is as follows. The 1st stage of the converter reduces NOX, because when a NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom from the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are stuck to the catalyst, forming N2. For example:

2NO=>N2+O2 or 2NO2=>N2+202

EGR has mostly to do with recirculating unburnt and/or partially burnt fuel (ie. HC's). Hence the name Exhaust Gas Recirculation valve!!!

Later.

 

[snowwind1990]

New results....
Much better, not quite perfect YET. They agreed to let Bart find his own speed((I watched for a while but I was getting a knot in my stomach,,he sounded awful like he was struggling)) for the test by calibrating it with externals...look at the dif.:
Passed Low speed test....955...state allows: 970
Failed High speed test:;;; 919...state allows: 878

I have a new free test in 10 days....get the cats even hotter.....
I CAN DO THIS!!!! shoot
Ma Ma M

 

[shojuan]

Kevin Ryan:
Sorry, the way it goes is as follows. The 1st stage of the converter reduces NOX, because when a NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom from the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are stuck to the catalyst, forming N2. For example:

2NO=>N2+O2 or 2NO2=>N2+202

EGR has mostly to do with recirculating unburnt and/or partially burnt fuel (ie. HC's). Hence the name Exhaust Gas Recirculation valve!!!

Later.

A three way catalyst cuts NOX emissions to about half of what they would be without. But I assure you, the purpose of EGR is for cutting NOX emissions, NOT hydrocarbons. Give me a break! An insignificant amount of exhaust flows through an EGR port to make a difference in HC "reburn". That's what the catalyst is for! The purpose of letting that exhaust back into the intake in to create inert gas air space in the combustion mixture for the purpose of lowering combustion temperatures which in effect lowers the amount of nitrogen oxides that are produced. Why do you think diesel engines produce so much NOX emissions? It's because of the inherently higher combustion temperatures of a diesel engine compared to a gasoline engine.

Rick

 

[snowwind1990]

on this second test;
NOx was cut in half(approx.), on the
HC:readings slightly higher on the low speed test
HC:readings slightly lower on the high speed test

NOx FAILED in high speed test by 41ppm. PASSED in low speed

Therefor: Higher HC less NOx

Ma Ma M

<small>[ October 13, 2002, 01:14 AM: Message edited by: snowwind1990 ]</small>

 

[shojuan]

That's because hydrocarbons help platinum catalyze NO2. Interestingly the Honda Insight has a trick little catalyst that combines a traditional platinum catalyst with a sodium and titanium compound that acts to store NO2. Under normal lean burn conditions (as much as 22:1!!! air to fuel eek! ) the NOX levels go up quite a bit and this gets stored in the sodium titanium substrate. The computer actually monitors the saturation level of this storage compound and when it's saturated then the computer richens the mixture which boosts the CO and hydrocarbons, the purpose being so the platinum catalyst can reduce the stored NO2 with the CO and HC. Then it's back to lean burn. Pretty trick.

Rick

 

[Kevin Ryan]

shojuan:

Kevin Ryan:
Sorry, the way it goes is as follows. The 1st stage of the converter reduces NOX, because when a NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom from the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are stuck to the catalyst, forming N2. For example:

2NO=>N2+O2 or 2NO2=>N2+202

EGR has mostly to do with recirculating unburnt and/or partially burnt fuel (ie. HC's). Hence the name Exhaust Gas Recirculation valve!!!

Later.

A three way catalyst cuts NOX emissions to about half of what they would be without. But I assure you, the purpose of EGR is for cutting NOX emissions, NOT hydrocarbons. Give me a break! An insignificant amount of exhaust flows through an EGR port to make a difference in HC "reburn". That's what the catalyst is for! The purpose of letting that exhaust back into the intake in to create inert gas air space in the combustion mixture for the purpose of lowering combustion temperatures which in effect lowers the amount of nitrogen oxides that are produced. Why do you think diesel engines produce so much NOX emissions? It's because of the inherently higher combustion temperatures of a diesel engine compared to a gasoline engine.

Rick

The second stage of the cat (oxidation catalyst I believe it is called) is for the reduction of unburned hydrocarbons and carbon monoxide by burning (oxidizing) them over the platinum and palladium catalyst. This aids the reaction of the CO and HC's with the remaining oxygen in the exhaust. For example:
2CO+O2=>2CO2 (If I remember my 2 years of college chemistry and 5 years as a shop owner with an average of 1,100 e-test repairs per year without a single failure in those 5 years). But your telling me that the cat (which is operating at approx. 8-900 degrees) is taking those COOL 8-900 degree exhaust gases and sending them back to the intake so it can cool down the intake air charge?

<small>[ October 12, 2002, 01:07 PM: Message edited by: Kevin Ryan ]</small>

 

[shojuan]

Don't try to teach me a chemistry lesson. Maybe you took baby chemistry for Pre Meds or something in college. I was a chemistry major. Do you think I am some country bumpkin or something? Owning a shop does not make you an engineer, so give it up. Yes, that hot exhaust cools the combustion chamber. You obviously doubt me so go talk to an exhaust engineer. And by that I don't mean some chump who works in a smog shop.

Rick

 

[snowwind1990]

Please keep me focused:::
KISS theory applied here: ?Get the cats as hot as possible just for the test sessions....

Someone suggested using 111-118 octane for Motorcycle application instead of the Berryman's ...any comments here.....

Of course dilute after. .of course.
Ma Ma M

 

[Kevin Ryan]

Well, Mr. Wizard, in that case you of all people should be able to tell me if my chemistry is correct or not. As far as engineers go, I've never seen one that could fix anything worth a crap. As far as beining a shop owner I was/am also a L1 and L2 certified master technician. I'm also a Gold Chrystler Master Tech. All I'm saying is that of all the E-test failures I've seen due to NOX have been mostly due to defective cat/s. EGR does have also help in the reduction of NOX. Relax dude!!! thumbs_u

 

[shojuan]

I was in a really pissy mood Saturday. Sorry for being an a**hole. Glad I didn't scare you off shoforum forever. thumbs_u

Rick

 

[shojuan]

Marlene,

Since good cats can cut NOX 50% compared to no cats maybe you can swap your y-pipe off of your other SHO to pass the test. Or if you don't think the cats on your other SHOs are up to ***** maybe Scott or some other SHO friend in texas would be willing to let you swap their y-pipe on so you can get Bart smogged.

Rick

<small>[ October 14, 2002, 05:13 PM: Message edited by: shojuan ]</small>

 

[matt59]

But your telling me that the cat (which is operating at approx. 8-900 degrees) is taking those COOL 8-900 degree exhaust gases and sending them back to the intake so it can cool down the intake air charge?

(New Diesels actually have a EGR Cooler for that very purpose).

Rick is Correct. EGR Displaces Oxygen to reduce the higher burn temp.
An Acyteline cutting torch is a perfect example, More Oxygen = Hotter Flame.
Cats do lower Nox by changing the chemical make up after the burn, EGR does this before the burn. In the late 60s the EGR came out to reduce the new Emissions threat, NOX. Also the little Retrofit (NOX) device was introduced to limit timming advance to battle NOX, Cats came out in the mid 70s and brought all the emissions down.

For what its worth.

 

[SHO Continental]

But your telling me that the cat (which is operating at approx. 8-900 degrees) is taking those COOL 8-900 degree exhaust gases and sending them back to the intake so it can cool down the intake air charge?
For what its worth.

No one is telling you anything.. this thread is 3 years old.

btw.. I see you're in simi valley, go to www.shocal.com and sign up!

 

[matt59]

The Text in Bold were from Kevin. I just wanted to chime in with my two cents. Someone might actually want to read this. :corn:

 

[jedhead]

My SHO would not pass the NOX part of the test the last time in spite of new O2 sensors, y-pipe with cats, and EGR cleaning. I had to pull the spout connector to pass.

Bob

 

[PhatSHO]

Re: Failed Emissions

SHORob,

I have a 95' SHO from Denver I bought new and I'm an now living in Phoenix and I had the same problem after I tried to pass emissions here in Phoenix too. I took my car to Goodyear for service and they did a carbon cleaning for me and at the time I didn't know what was involved to complete that process. I failed with a NO2 of 0.12 and passing in AZ is 0.02, once that was completed the car passedwith a passing of 0.008 I think thats what it was and I have not had a problem since. The guys here have a lot of good ideas but try that too it couldn't hurt and I have noticed at least here in AZ my car is now running like it was when I was in Denver, minus the snow....lol Good luck.

Virg

PhatSHO