My EF has high NOx and the timing goes off for some reason. we adjusted it but then a couple of days later i guess it went off. im adjust it again to see if it stays. also i have high nox. how can i get rid of that? change the cat?

 

nox can be high from really hot cylinder tempratures( carbon deposits, too high timing, not enough fuel) cats reduce NOX

 

yeah my timing is off by 5 degrees... ill get it done. i dont have a timing gun. i have to go to a homies house and hes always at work. also my cat is still the original OEM and the car almost has 200k so its about time to change that.

 

retrad the timing by 2-3 degrees and go again you should pass. my oem cat has 300,000 + miles it passed smog last year. Don't waste ur money on a cat. OEM cats will last very long time!

 

really? because the smog tech said that the cat might be worn also =/. he mentions "is the the original cat? it might not be restricting as much as its suppose to, if i were you i would get a new cat to be safe. Also the timing is off 5 degrees. if u make it higher theres a really good chance you can increase the nox. nox is caused by high temperatures in the engine. so...if you can get those fixed you should be fine." also before this we set the timing it was just right. then we did a tune up because there was oil in the spark plugs due to bad seals. i fixed the seals so theres no oil in there anymore and did a tune up. we changed only the plug wires, plugs, oil filter, and oil. then we took it to the test place. it didnt pass obviously. then i bought a new thermostat and air filter cause the air filter was REALLY BAD! im gonna get a new cluster tomorrow at the junk yard and get my timing done thursday again. but iono i think i might need that cat to be safe...what do u think?

 

help please ^_^

 

what kind of gas are you running?

 

If you look at the test you will see an o2 reading if it is above .3 of 4 probably your cat is toast. But the timing thing is just as important. Set up either at spec or one degree less advance. This will lower nox too.

If you haven't changed it I would recommend a new o2 sensor too. I would do both the cat and the o2 at the same time and that is it.

 

the cat is easy to blame. my car had 308,000 (STOCK CAT) miles when I smogged my 89si. It failed the first time second time it passed. All I did was retard the timing and bam it passed. It barely passssed though.

if your motor is running shitty then you have a whole new problem. you can try and change the cat and try retard timing by like 2 degrees and change 02, new plugs, wires, cap, rotor but then again if you fail which most people do. try it **** you never know you might pass. old honda motors have a hard time passing NOX, HC!

 

Hey Bossman,

What's a bootle? In your sig. You mean bottle right?

Passed with stock cat at 308K That is pretty darn good.

 

I have a tsx swap in my dc2 with n20 .


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thesmogman &raquo;</TD></TR><TR><TD CLASS="quote">Hey Bossman,

What's a bootle? In your sig. You mean bottle right?

Passed with stock cat at 308K That is pretty darn good.</TD></TR></TABLE>

 

I have retarded the timing below factory spec to squeeze by on Nox before it works if its not too far off.

 

so change my o2 sensor also? i bought a new thermostat if that helps at all. the thing is i bought this off someone not too long ago, about 11 days ago. this is what the inspection report reads...well..the part that failed. i dont know how to read this so forgive me. ima post it up here. besides the timing this is the ASM emissions TEST results part. i didnt include the 25mph because that one passed.

test
15mph

rpm
1829

co2 meas
14.65

HC (PPM) -"IT was highlighted through here"-
MAX-127
AVE- 31
MEAS-94

CO(%)
MAX-0.79
AVE-0.10
MEAS- 0.38

NO (PPM)
MAX-825
AVE-237 -"that wasnt highlighted"-
MEAS- 1066 -"to here"-

results
fail

iono what kind of gas dude was using...most likely cheapo creepo gas. i put cheveron if not shell and vice versa now that i have it. the cat does look pretty old. ima fix my timing today and hope it doesnt go off again like it did hella randomly, so i replace the o2 censor, and cat? btw i appreciate you guys for helping me out on this situation. im so lost, a friend told me to come to this site.

 

By your numbers, It looks like you just needed to do the timing.
On my car 2 degrees = 250ppm for nox. Which would get you to pass.
That is 1 degree advanced from spec to 1 degree retard from spec.

So have you tested it?

 

yeah i have and he said that its off by 5. this was recently. the numbers i showed u were from the previous owner. what should i do? im going to get the timing done today since i dont have the tools for it

 

Get the timing done and go for the test. If you were off by 5 degrees I would say that is your only problem.

 

alright, ill do it today then get it tested tomorrow because a friend of mine has all the tools for it and he gets off of work at about 6 to possibly 7. hes a commuter so yeah it takes a while. ill visit the smog test center tomorrow. ill let you guys know how it goes and we'll see whats happens. ill update you guys

 

im open to more suggestions. do i really need that thermostat?, o2 sensor, and cat? or should i just do timing.

 

Edit:reread. Saw it passed at 25

Did it pass at 25mph? If it did,then the smog tech didnt do a proper warm up. I still think the Cat's on the edge of being bad,but if he started the car,drove it on the dyno then tested,an old cat will have a problem passing 15 mph. If it did pass at 25mph,drive the car hard,dont shut it off at the station. Keep it nice and hot and retest. Ive seen old cars have this happen and w/ a good proper warm up it should pass...even if barely. Let us know how it goes.

 

yeah im gonna lets you guys know. ima take thesmogmans advice and change the o2 sensor since its due anyways for peace of mind. im thinking about changing the cat for peace of mind too so i dont need to go through all this bullshit in the future. but ill take your advice as well. that sounds like a better idea also. drive the **** hard then dont shut it off. i think that was the problem too. cause we shut the motor off so maybe it cooled down. when we got there we shut it off and he was helping someone already. then he turns it on and puts it on the dyno. so yeah thats probably what happened also but the timing was still off. i didnt get to do it yesterday im going to do it today and change the o2 sensor. on the weekend DMV is closed and i dont feel like paying a late fee so thats why im thinking while im at it i might as well change the cat on saturday. also ima put some premium fuel ^_^

 

what year and model is it???

if it is a dx, it should have an EGR, and that helps reduce nox by a lottttt

and if its an si, it shouldnt have an EGR, the thing to do is superheat the cat,

sit there for 5 minutes at 2500 rpm, trust me, i do smogs for a living

 

its not as easy as you think trial user.

 

ok another concern now is that my temp tag is expired as of the 30th. ive gotten so many nice support from all of you. but i cant use it now that my temp is done. this is the situation. the car isnt under my name yet...so how do i get another temp w/o that? show them the bill of sale? let me know asap so i can get to the smogging thank you guys

 

Go down and start the change of ownership at the DMV. You will have to pay the taxes and such.

They will tell you that you need to do the smog. Then ask for an extension.

Then you will have to go back to show the smog and they will give you the tag's.

 

cool, thanks man youve been a big help. once i do that ill put the work in the car and tell you guys how it goes