car will not pass smog

[angel4ever]

I have a Nissan 240 sx 1993 it will not pass smog. I have done several things to the car and still will not pass. I have done a high mileage oil change,changed spark plugs and wires, also changed cadillac converter. I have taken it 4 times and will not pass. what is not passing is the nox. It did go down from 8.25 to a 7 then 5.25 it has to be at 2.50 in order to pass. Can someone HELP please.

[xFidelity240sx]

Cadillac coverter lol - Check your EGR system. Clean it and make sure everything on it is working properly and your NOx levels should go down. Where do you live? I assume AZ cause our NOx is 2.50 for the standard.

[angel4ever]

Yeah, I do live in AZ . Lol sorry did I not use the wrong spelling. I did check the EGR system one of my hoses was torn. I replaced it then went to get the smog. I didn't pass but it did go down to the 5.25. what else can I do? My car also runs a little rough in neutral or at a stop sign. A kind of seems like its choking or it wants to stall out.

[mixeds14]

Have u change ur pcv valve. That might help

[Razi]

Take the red allen head part out and clean it with a large pipe cleaner like this. Use carb cleaner or something too.

Usually there is a lot of carbon build up back there.

[angel4ever]

No, I haven't I bought the part today But no one could find it. Thanks for the pictures. I'm going to try it tomorrow. I have a book on my car and still couldn't find it from the book. Thanks

[angel4ever]

That's exactly what my car looks like. I will let you know if this works tomorrow. Ethan's again.

[mechanicalmoron]

Take the red allen head part out and clean it with a large pipe cleaner like this. Use carb cleaner or something too.

Usually there is a lot of carbon build up back there.

What's behind said allan bolt?

OP, you might try seafoam. Seafoam it through the brake booster, and give it a dose in the gas. After, I suppose, cleaning behind that thing, whatever it is.

[Razi]

It has something to do with the EGR.
I think the gasses pass through that spot.

[angel4ever]

The pictures you sent is this were the PVC valve is at or you just suggest to clean there also. If so do you have pictures or video were the PVC valve located?

[angel4ever]

ok so i was told my EGR was not cleaned they only changed the hose. how do i clean it and what do i need to buy?

[angel4ever]

Were do I add the sea foam?

[Razi]

People usually use the brake booster hose since it's huge.

We have a thorough article here on how to use Seafoam:
http://www.nicoclub.com/archives/how-to ... t-way.html

[Dimitri]

quote="angel4ever"]........ what else can I do? My car also runs a little rough in neutral or at a stop sign. A kind of seems like its choking or it wants to stall out.[/quote]

1.Was the idling issue there before failing smog for the first time?
2. Did you drive the car around for 30 minutes before going in for the smog check?
3. Did you let the engine running while you were waiting your turn?

[mechanicalmoron]

........ what else can I do? My car also runs a little rough in neutral or at a stop sign. A kind of seems like its choking or it wants to stall out.

1.Was the idling issue there before failing smog for the first time?
2. Did you drive the car around for 30 minutes before going in for the smog check?
3. Did you let the engine running while you were waiting your turn?

If they don't care, or don't have a rule against it, it probably wouldn't hurt to run the motor at 3-4k rpm, if you can do so without overheating, for a few minutes directly before the test, like ending right as you pull up for it.

In fact, if you could get the temp to climb a bit past where it normally stops, but still without overheating, that would probably be better. But don't listen to me, you'll probably blow your motor over a smog test

[GTR PrYdE]

I have passed smog on my ka-t with only a new cat that I heated up pretty good and left it running when I got there. It barely passed.

WD posted some stuff about using denatured alcohol in the gas tank, after running that gas tank pretty low. I had to do this the last time I had my car inspected, as the crappy magnaflow cat started wearing out and gave me bad numbers at the inspection office. I think he mentioned something about retarding the dizzy a couple of degrees to help get the smog down. Hopefully he'll chime in. Good luck