This is topic Trouble passing Smog?...Nitrogen Levels to high in forum Tech Talk at Northern California Ford Owners  .


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Posted by 90FoX (Member # 1974) on :
 
ok well i have a 1990 5.0 and it has about 155,000 miles on it...i have to smog it for registration. it has bbk equal length headers and a high flow bassani x pipe with dynomax bullets...

the smog tech told me that the new smog laws require them to check nitrogen levels and that the old smog laws didnt require that.

and my car is at like 900-1200 and the max is "500" something around there. anyways that leads me to this problem. I CANT PASS lol.. the x pipe has cats and they are brand new, less than a year.. the exhuast does smell like the car is running fat(rich)...any suggestions on what i can do to get my car the way is used to be without having to throw on the old h pipe with 4 cats.
- the smog tech told me that its not passing because the car needs to have 4 cats... im guessing that my car isnt running right. anyone encounter this probelm..

maybe my 02 sensors are bad and are tricking my ECU to thinking that the engine is running lean.

should i try to clean my mass air sensor?
pull the codes?
any help would be great
because i dont want to just pass smog with 4 cats and still have my cars tune way off.
thanks

PS- i have not noticed a drop in gas milage..i have 3.73's and am getting about 215-230 miles on a full tank

[ May 19, 2004, 06:19 PM: Message edited by: 90FoX ]
 

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Posted by mtbaughs (Member # 4052) on :
 
With the X-pipe sometimes you need to bring the car straight in from beating on it and get the cats real hot just prior to the smog dyno. I know this has worked for quite a few people.
 

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Posted by 94gt (Member # 3060) on :
 
I had a friend that couldnt pass with his truck, so he drove all the way there in like 2nd. When he pulled up, the said the cats were glowing, and that it helps them to get hot... I guess so they can burn off more junk?
 

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Posted by TheBrain (Member # 35) on :
 
NOx levels go DOWN when the engine is running rich
So if your car is running "fat" then you would not have failed NOx
If anything your car is either lean or the EGR system is not working
Put 91 octane in your tank prior to getting your car smogged. It may cause a slight increase in HC and CO, but your NOx level will go down
What smog tech told you that you need 4 cats to pass but didn't visually fail your car for an illegal x-pipe ?!?!?!

Good Luck
Brian

[ May 19, 2004, 06:38 PM: Message edited by: TheBrain ]
 

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Posted by 90FoX (Member # 1974) on :
 
i dont think its the cats that are the problem.. i think its something else...my cats were warmed up... he even held the rpms at like 3000 then checked ... somethings up with my car...just recently the exhuast started to smell like the car was running rich...

also a strange thing that happened to me is one day i rev'd the car up and the rpms just stuck there above 1000 for a while then dropped ... hasnt happened again though.. wierd...
 

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Posted by 90FoX (Member # 1974) on :
 

quote:

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Originally posted by TheBrain:
NOx levels go DOWN when the engine is running rich
So if your car is running "fat" then you would not have failed NOx
If anything your car is either lean or the EGR system is not working
Put 91 octane in your tank prior to getting your car smogged. It may cause a slight increase in HC and CO, but your NOx level will go down
What smog tech told you that you need 4 cats to pass but didn't visually fail your car for an illegal x-pipe ?!?!?!

Good Luck
Brian

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quote:

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Originally posted by 90FoX:

quote:

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Originally posted by TheBrain:
NOx levels go DOWN when the engine is running rich
So if your car is running "fat" then you would not have failed NOx
If anything your car is either lean or the EGR system is not working
Put 91 octane in your tank prior to getting your car smogged. It may cause a slight increase in HC and CO, but your NOx level will go down
What smog tech told you that you need 4 cats to pass but didn't visually fail your car for an illegal x-pipe ?!?!?!

Good Luck
Brian

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i think that the x pipe is 50 state legel
i dont remember thought..ill check with bassani

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nope its not a carb certified part or 50 state legal though many pass with it on the car
 

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Posted by HungryHippo (Member # 537) on :
 
i think nox comes from hot cylinder temps and malfunctioning egr. but it could also be the o2 sensors if they're old
 

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Posted by 90FoX (Member # 1974) on :
 
yea i just got the car like two years ago with about 140,000 miles on it, and i have no way of checking if they were ever changed

i messed with my timing a long time ago but gas prices shot up so i didnt want to keep it at about 15 degrees so i choose to move it back...maybe its not adjusted properly

so ill check my O2's (probably change them, what kind should i go with?)
clean my mass air
run some 91
check my timing, btw if i choose to run 91 should i leave it at 14-16* or will it help my nox level if i keep it lower at about 10-12*?

also how do i run tests on my EGR?
if i remember right... doesnt my egr only kick in after 3000 rpm? i dont think he took it that high...
what tool will i need to check the egr?
thanks again
 

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Posted by TheBrain (Member # 35) on :
 
The smog tech should have checked your timing (it is part of the test) Spec is 10* +/-3* 14* of timing is a failure
Your best bet would be setting the timing @ about 8* BTDC
As for your EGR, You can check to see if the passages are clear by popping the top off of your EGR solenoid (located on the back side of the pass. side shock tower) and put your finger over the hole while the engine is running. By doing this you will be blocking the vent forcing vacuum to open the valve. This will test the EGR valve, vacuum lines and solenoid passages. The engine should run poor or die with the vent port blocked. If it doesn't, look into the valve and see if the EGR is opening.
You can also test your EGR system by running a KOER test and check for codes

Good Luck

Brian
 

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Posted by v-town coupe (Member # 2771) on :
 
i recently have had a couple problems with nox on a couple of cars i have had smogged so may be this will help
1- you need to make sure that ur can is in proper working order make sure the timing is correct mainly my mitsubishi wouldnt pass i dialed in the timing and i came under the max nox!
2-make sure u take it to a GOOD SMOG SHOP and by that i mean make sure the warm it up on the dyno before they smog it usally i drive it around and get it warmed up and the guy i go to warms it up on the machine and takes a look at the numbers before he tries to go into test mode!
3- i would recommend using this tuff called CLEAN POWER its like an octane boost and it likes almost like a tall bottle of vodka and that shit kills the nox i have used it in a shit load of cars and it helped all the ones that did not have some kind of mechanical failer for ex: i took my grandmas civic to the shop and at first the nox was at 1435 max allowed was 731 so i put the clean power in and some 91 oct. gas from chevron and drove it hard for about a week it dropped the nox to 753ppm(parts per millon) but then i knew it had to be the converter replaced that and it went down to 23ppm and passed!
so hopefully this helps smog is the main reason why i stopped using 5.0 bodys to house all my motor creations i will just use ones that sre pre smog with new technology feel lucky its not a test only good luck!
 

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Posted by v-town coupe (Member # 2771) on :
 
i forgot to mention i noticed u have bullet mufflers and i dont know what it is but everyone ive seen with those has a hard time passing smog its basically a glass pack!
 

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Posted by TheBrain (Member # 35) on :
 

quote:

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Originally posted by v-town coupe:
2-make sure u take it to a GOOD SMOG SHOP and by that i mean make sure the warm it up on the dyno before they smog it .....the guy i go to warms it up on the machine and takes a look at the numbers before he tries to go into test mode!

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quote:

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Originally posted by v-town coupe:
damn well he fucked up didnt he?

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Not really, he's just pushing his luck a bit

I got a stern warning from the state for doing the same thing.
 

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Posted by shade- (Member # 298) on :
 
lol!

[ May 20, 2004, 08:22 AM: Message edited by: shade- ]
 

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Posted by shade- (Member # 298) on :
 
.

[ May 20, 2004, 08:21 AM: Message edited by: shade- ]
 

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Posted by shade- (Member # 298) on :
 
...
 

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Posted by 90FoX (Member # 1974) on :
 

quote:

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Originally posted by v-town coupe:

1- you need to make sure that ur can is in proper working order make sure the timing is correct mainly my mitsubishi wouldnt pass i dialed in the timing and i came under the max nox!

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sorry but what exactly is a can?

and Brian ... would you suggest i run it at 8* btdc and run 91 or just stay with 87?

thanks for all that help again..i have an extension to pass smog until the 31st of may


PS- i was reading online and if i recall correctly nox gases are inert and cannot be burned again. which leads me to believe its not the cats because they wouldnt be able to burn the gases, is this true?

[ May 20, 2004, 01:53 PM: Message edited by: 90FoX ]
 

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Posted by TheBrain (Member # 35) on :
 
I would suggest 8*-10* AND 91 octane

It's not the NOx that is inert, it's the gases allowed back into the engine (exhaust) that is inert. Thus taking up space in the combustion chamber lowering cylinder head temps (high cylinder temps is what creates NOx)

Brian
 

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Posted by 90FoX (Member # 1974) on :
 
ok cool. thanks alot brian you've been great at helping me out and clearing things up.. just one more question...to test my egr i was told there is a sensor right behind my pass shock tower and i lift a "tab" and plug it up and if my motor is still running it is clear that the egr is functioning properly... and if the motor dies or stumbles the egr valve is clogged.Now this is opposite of what you were saying... just double checking of which one is right? i dont want to falsly blame the egr...

ill probable change my plugs, o2's and check my timing and test the egr and heat my cats up and i should be good...i dont know if you care but ill post as soon as i get the results of my smog

thanks agian

[ May 20, 2004, 03:40 PM: Message edited by: 90FoX ]
 

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Posted by TheBrain (Member # 35) on :
 
If you plug the vent on the top of the solenoid and the idle quality does NOT change, you EGR system is NOT working
The solenoid vents the vacuum through the top (you'll see the vent after you pop the cap off) when you physically plug the vent, the vacuum is then applied to your EGR valve causing it to open, making your engine idle rough or die

So I am right

I have been a smog tech for 11 years, so trust me

Brian
 

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Posted by 90FoX (Member # 1974) on :
 
no i didnt say you were wrong i was just checking
 

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Posted by vpr_klr (Member # 3353) on :
 
With a 155k miles on the motor, maybe your egr ports are plugged up. You can remove the upper intake and use a metal coat hanger to knock out some of the chunks, just remember to use a high power shop vac when you are done, just my 2 cents.
 

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Posted by 90FoX (Member # 1974) on :
 
where is the can?

i checked the egr its fine... my timing is at ten...what else?
 

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Posted by v-town coupe (Member # 2771) on :
 
sorry its a typo i meant to say make sure ur car is running properly such as egr valve ports clean and prope timing etc. etc.
 

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Posted by 90FoX (Member # 1974) on :
 
o ok ...well im gonig to check my O2's sensors, anyone have a clue on how to do this.

i was told to use a voltmeter, but what should the voltage be? ect.. where do i check these things?
 

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Posted by 90FoX (Member # 1974) on :
 
well he said he will pass me with the x on the car but the only problem is my nox level is to high otherwise i would have no problem. hes not that strick on my visual anyways.

but my car seems to be running lean so im going to check my o2's if those are ok ... my last chance is to throw the stock h on ... unless someone has any other tips...but before i toss the h back on ill check out that clean power solution.. also im going to run 91 with some injector cleaner

thanks again
 

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Posted by 90FoX (Member # 1974) on :
 
if my o2 sensors are bad, would it send some codes to my computer or should i just swap them out?

also the only things that came up when i checked for codes were for "EVP voltage to high (SONIC) or PFE sensor voltage high or out of spec" what is my EVP and PFE? could this also be causing my nox levels to rise?


 

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Posted by 90FoX (Member # 1974) on :
 
TtT
 

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Posted by blind (Member # 3052) on :
 
as far as I know, high nox is the cats or running lean...high hc or co is running rich (will have very low nox levels to combo with that).

good luck if it were me, I'd swap the stock H back on
 

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Posted by CobraSVT (Member # 2309) on :
 
I would double check the EGR. Mustangs have an issue with the EGR after about 100k.. If you can have someone put you car on a sniffer and check to see if you are lean or rich. If you are lean you can change a bunch of parts with no results. My blazer is in a lean condition and it barely passed. Is it failing both the low speed and the high speed or just one of them?

The high flow cats are not legal in Ca. Stupid smog laws..

Eric
 

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Posted by 92stangLX (Member # 3252) on :
 
I had trouble passing because I was high on the NOX. I changed my EGR and managed to pass. This new test is checking to make sure your EGR (and cats) is working properly. You might want to try changing the EGR valve and sensor.
 

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Posted by 90FoX (Member # 1974) on :
 


[ May 23, 2004, 09:28 PM: Message edited by: 90FoX ]
 

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Posted by rico91stang (Member # 2389) on :
 
I have heard of old school guys pouring rubbing alcohol in their tanks before an emmission test and pass with flying colors. Would that work?
 

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