How to lower "NO" levels for a SMOG test

I just failed a SMOG test because the reading said my "NO" (also called NOX) levels were a couple of units above the acceptable level at the 25 mph test level. I think my were 281 and it needed 269 to pass. Is there anything that can be done in order to lower the NOX levels a little bit? Super-Unleaded? Fuel Additives. The car is kind of old and I would rather not get a whole new catalytic convertor.

Any ideas or thoughts would be greatly appreciated.

Thanks!

Reply to
Brantster
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What kind of car? It could be a failing EGR (exhaust gas recirculation) system. Probably plugged up. I've had the EGR valce carbon up on my car and stick. I just took it off, sprayed carburetor cleaner in in, moved the valve back and forth until the carbon broke free and all was well.

Reply to
Paul Hovnanian P.E.

Make, model, engine, transmission and year of the vehicle?

Reply to
Daniel J. Stern
1989 Acura Integra, 4 cylinder, automatic.

Thanks!

Reply to
Brantster

High NOx emissions can be caused by, among other things:

-Overly advanced ignition timing

-Faulty EGR component(s)

-Excessively lean mixture -Dirty fuel injectors -Faulty O2, MAF, MAP and/or temperature sensor(s)

-Carbon buildup in combustion chambers

-Faulty reduction catalyst in catalytic converter

-Oil burning

DS

Reply to
Daniel J. Stern

What were the other gas readings for both 15 and 25 MPH?

NOx is related to heat / car running lean.. Possibly related to the EGR valve, a poor air fuel mixture, maybe even chunks of carbon in the cylinder that raise compression and thus heat.

Don't blindly replace parts, its too expensive, take it to a shop for a diagnosis.

__________________ Note: To reply, replace the word 'spam' embedded in return address with 'mail'. N38.6 W121.4

Reply to
Barry S.

Had the same thing happen to a BMW I had some years ago, except the NOX levels were higher than yours. I used a can of that 'Pass or Don't Pay' type of fuel additive (I don't remember the exact name) to clean out the fuel system. It passed with flying colors. If it didn't, I could've send in the reciept for a full refund of the purchase price, then looked for more extensive solutions. You can find this stuff at any auto parts store, it costs about $10. Follow the useage directions printed on the can.

Good luck

Reply to
Bubba Kahuna

But that way isn't even half-assed. It's quarter-assed at best. All it does is hide the problem from the emission tester.

DS

Reply to
Daniel J. Stern

As long as it gets you by......

Reply to
Uncle Dodo

That's the objective. Who the hell cares how much the car puts out after it passes the test?

I run my own car with the emissions crap removed and/or disabled, and just hook it up temporarily when needed for smog check.

Reply to
Roger Blake

Exactly!!!! Where's the tree-huggers. Come on tell us how irresponsible we are.. SCREW EMISSION TESTING!!!!!

Reply to
Uncle Dodo

While I am not a rabid environmentalist, I do enjoy hunting and fishing, and believe in safeguarding our natural resources.

I'm not going to tell you that. I do wonder about the science behind some air quality issues, however. There wasn't a catalytic converter on Mt. St. Helens when it belched tons of pollutants into the atmosphere, and any theories about previous extinctions are just that-theories. I'm thinking that if everyone rode cows, rabid environmentalists would be screaming about methane pollution. We as a species cannot exist without having some impact, even stone age man had to kill something to survive. I would be more willing to adhere to strict emissions testing and compliance if politics and emotion were removed from the debate, and changes were measurable and provable. YMMV Sally sells sea shells by the sea shore because rough men stand ready to do violence on her behalf.

Reply to
Mark Pilcher

Dude, you should be shot. Not sure if eternity in hell for you should be an exhaust pipe shoved up your ass or maybe inserted in your mouth. Either way, the pipe needs to be very hot, to cause you maximum and extreme pain. May you get lung cancer or some other incurable disease that makes breathing impossible. And when you are laying on your hospital bed, gasping for air, I'll send Jack LaLanne in to do jumping jacks on your chest. And if that isn't enough to send you over to the other side, I'll find the fattest and ugliest woman in the hospital (or maybe just your wife, same thing), and have her sit on your face to smother out your final time on this planet.

Reply to
Frog

Check your EGR system (particularly for clogging), it functions by lowering peak combustion temperatures to reduce NOx formation from nitrogen in the air. Does th eCar have a combo reduction (for NOx) and Oxidation (for CO and HC) cat? I doubt fuel additives will help, though additives (either already in th egas delivered to the gas station or added to the vehicle's tank, w/ oxygenates *might* help CO or HC *slightly*.

Reply to
The Masked Marvel

NO is caused by high temperatures and high compression. The "lucky" way to avoid NOx is to keep your engine as cool as possible before inspection. Perhaps drive to the inspection station, park it near a mall, leave the car parked for an hour, THEN drive across the road to inspection. Other readings may be higher, but if the engine is cool enough when they test it, you might get away with an emissions "compromise".

Two years before my last inspection, I received a 900 out of 1700 NOx allowed. I had warmed up the engine pretty thoroughly. During the latest inspection I turned the car off, cruised downhill (in-line) to the inspection station, in about 65 deg.F weather. The reading was roughly 250 / 1700. Finding a station with a downhill approach is very helpful :)

Oh, and some additives cause the combustion chamber to burn even HOTTER. This will get rid of "deposits", but it will also raise your NOx levels even higher. Self-cleaning ovens also use super-high temps during their cleaning process. If you use your own additives, make sure they're not in the tank during inspection.

Dan

Reply to
dstvns

"Tibur Waltson" wrote in news: snipped-for-privacy@news.bubbanews.com:

snipped nasty emissions

I've been living in an 'enhanced' area (ASM test) since the inception of the program. I've had no problems getting my vehicle to pass since ASM testing is easier to pass then the TSI test. I only had to make sure that the timing was spot on and the EGR was working correctly.

Reply to
Death

Octane boosters containing MMT should reduce NO, but slightly increase HC and CO.

or just try again and hope instrument error is on your side this time

Reply to
R

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