So...I Failed Smog

[Booster-Shot]

Yes, its true and Im bummed out! My car passed in every section except for NOx. I have no idea what Nox is, but the average rating is 250, the maximum is 750. My car happenend to pull an impressive 1450.

So Im trying to find out how to lower that number signifigantly. What causes Nox? The guy said it could be my EGR valve, which I think is right. I took it out and it was filthy. So I cleaned it up and figured it wouldnt be a problem. Should I buy a whole new valve or just trying replacing other stuff first? Thanks a lot-

 

[hereitcomes]

Well if your EGR is bad, and you know it is bad I would suggest changing that for starters. Check the flow of your cat as well, it could be clogged or not functioning properly.

 

[Phil97GST]

can an afc help with the smog???

 

[absolute_DSM]

If I know right, a high NOX count means youre running hot/lean.

A good EGR would be a good place to start. Make sure the solenoid and valve are good and you dont have a vac leak to and from the solenoid.

 

[spyderturbo007]

NOx refers to nitrogen oxides. The "x" is just there so they don't have to write out evey oxide. It's a lot easier than writing out NO, NO2, N2O, N2O3, etc.

I also agree with everyone above, start with the EGR.

 

[housegsx]

Just an idea... If they sell E85 out there you could try filling up with 1/2 or 3/4 tank of that. I don't know if that'll work, but I'd like to see the smog results.

 

[Dark_Horse]

Just an idea... If they sell E85 out there you could try filling up with 1/2 or 3/4 tank of that. I don't know if that'll work, but I'd like to see the smog results.

E85 does indeed lower your emissions. I used it to lower my CO levels from 21.7x to 19.76. No other changes were made except the addition of about 25% E85 to the tank.

The only problem with using E85 to pass emissions in your case, is that running 100% E85 only lowers NOX emissions by 10%. So unless you can get closer to the upper limit, it's not worth it.

If you decide to give it a try, you'll have to change your settings on the SAFC to run a low percentage of E85. I'd suggest trying 30% E85 to start. With 550cc injectors, you need to set your SAFC to -10.82%. (I'm assuming that to run pure gasoline with 550cc injectors and a SAFC, your running around -17%?)

Or...You could just put in about 70% E85 and zero out your SAFC.

http://www.cleanenergy.org/programs/programs.cfm?ID=28&parent=1

 

[Dark_Horse]

You could also have incorrect base timing which also causes high NOX levels. High base timing = high NOX levels.

See chart below for better reference

 

[TheClaw]

I just passed last week - I only had to put a stock turbo-back on, and pull some fuel at idle.

I also have 660's, a 255, 272 cams, etc.

Do you have a stock exhaust? A cat works wonders!