High NO wont pass OHIO e check help!

[atvkid4eva]

Hye guys i have to have my 88' ranger e checked here in ohio and everything passed besides the NO level. the truck has a brand new Catalytic convertor and exhaust and dosent throw and CEL's here are the results of the test any help would be great since i dont know where to star:

ASM: Reading Limit

HC 24.9 PPM 208.0

CO 0.00 % 2.60

NO 1853.2 PPM 1363.0

C02 14.60

so the HC is low but the NO is really high..i dont believe i have an EGR valve on this truck so what else could it be?

 

[atvkid4eva]

it has a brand new catco single catalytic convertor..could this be the problem seeing that they come from the factory with two cats?

 

[atvkid4eva]

anyone?

 

[Big Jim M]

Perhaps you have answered your own question.. If you have ALTERED the cat system why would you even have a chance to pass inspection?
Big JIm

 

[Hahnsb2]

Cat shouldn't be the problem. As I understand it, the factory 2 cat system has two separate stages in separate cats, singe cats combine both stages in one cat. I've never had a problem passing with my single cat but they don't measure NOX here..

 

[atvkid4eva]

well big jim...the truck came with the cats cut off and the dual cat setup is very expensive compared to the single catco cat..i dont kno why a company would make a replacement cat that dosent allow you to pass inspection? anyone else have any insight on how to lower the NO level?

 

[Big Jim M]

High nox

well big jim...the truck came with the cats cut off and the dual cat setup is very expensive compared to the single catco cat..i dont kno why a company would make a replacement cat that dosent allow you to pass inspection? anyone else have any insight on how to lower the NO level?

High NOx is indicative of high combustion temp. There are 3 ways you usually get it down, they are: more fuel, repair EGR, or less timing.

One other small way is if you have failed at IDLE then adjust the idle UP to a grand or so and see if it passes there.

A very small air leak on the air tube or otherwise in the intake can cause high nox also. (less fuel)
Big JIm

 

[atvkid4eva]

yeah they do the emission test at about 30mph and i dont believe my 88' has an egr system does it? how hard is it to adjust the timing?

 

[Hahnsb2]

The easy way is to just pull the SPOUT connector before taking it through, it sets the timing at a base of 10*, I did this with my 2.9 just to be safe. At school I used an emissions machine type thing and got around a 25ppm drop in HC just by retarding the timing by removing the spout connector.

And correct, no EGR in 88.

 

[BRUTUS_T_HOG]

i would check the ignition timing and turn it down if its excessive. pull the SPOUT jumper when you check it.

the low CO and HC along with the high NOX tells me that you're running lean.

you should check for vacuum leaks, even small ones can make a difference

 

[dernst]

Nitrogen Oxides (NOx)*
NOx is formed inside the combustion chamber when excessive heat is present.

A list of common causes of NOx related smog check failure:

1. As usual check the timing first. Advanced timing can cause extra NOx.

2. The next thing to check is the EGR system.This system is designed to reduce Nox. It consists of a EGR valve, vacuum hoses, one or more vacuum switching valves or solenoids. Its job is to reroute a small amount of exhaust gas back into the engine to help reduce combustion chamber temperature. Not all vehicles have an EGR system.

3. Next thing to check is the air / fuel ratio. If the vehicle is running to lean, NOx emissions will increase.

4. Some possibilities are a restricted fuel filter, low fuel pressure, vacuum leaks, oxygen sensor, load sensor such as a map sensor, air flow meter.

5. Check the cooling system. An extra increase in water temperature will increase NOx production.

6. A defective catalytic converter can also increase NOx. The Cat. reduces NOx that has already been produced.

7. Check to see that the air coming into the engine is not over heated. Some vehicles have a vacuum controlled air valve which switches the incoming air to hot air from the outside of your exhaust manifold.This should only happen when the engine is cold. If this system malfunctions and sends hot air all the time.Your Nox could go up. This system is called T.A.C. ( Thermostatic air cleaner )

8. There is another system similar to the one above called E.F.E. ( Early fuel evaporation ). This system routes hot air under the intake manifold. This helps keep the fuel in the vapor state. If stuck in the hot mode Nox emissions could increase and cause a Smog Check failure.

 

[atvkid4eva]

ok where is the spout connector located at? could someone maybe show me a pic of where it is on the 2.9?

 

[Big Jim M]

Should be

ok where is the spout connector located at? could someone maybe show me a pic of where it is on the 2.9?

About 6 inches or so up the wire gonig to the distributor. Pull it to see what the timing is at idle. It adds about 3* at full timing when it is in place.
Big JIm

 

[atvkid4eva]

you mean the main wire going to the middle of the distributor? on my 2.9 the main power wire dosent have anything on it..just looks like a spark plug wire? i need a pic lol

 

[atvkid4eva]

so this is the only think under my hood that i believe is the spout connector :

so you guys think if i just pull it out and go get it re e checked it will lower the NOx enough to pass? then i just put it back in?