smog failed nox
02-26-2006, 01:11 PM
#1
Honda-Tech Member
Thread Starter
Join Date: Jan 2003
Location: SO CAL, ca, us
Posts: 1,567
Likes: 0
Received 0 Likes
on
0 Posts
smog failed nox
i live in socal
my smog numbers were fine except for NO @ 25MPH
i have a d15b7 with a d16a6 cam and an adjustable cam gear
also, 2.25 piping with a new cat
don't ask me to search because i have and couldnt find anything that specailly pertains to failing @ 25 mph NO.
also, high nox levels may be due to running lean, but my question is what would cause a stock motor (basically) to run lean and if so how can i make it rich without installing a fpr or something
in regards to timing i had already retarded it to 14btdc from 16btdc.
new plugs/wires/dist cap/rotor
fresh oil change
running 87 octane and i boned out hard right before the smog test
my car doesn't overheat
i need somebody to tell me what the problems can be so i can get my tags renewed
edit i dont know if this will help but let's see.. if i turn off my car then try to turn it back on within like 5 seconds or so it will start up but then stall out.
Modified by jerbear! at 10:05 PM 2/27/2006
my smog numbers were fine except for NO @ 25MPH
i have a d15b7 with a d16a6 cam and an adjustable cam gear
also, 2.25 piping with a new cat
don't ask me to search because i have and couldnt find anything that specailly pertains to failing @ 25 mph NO.
also, high nox levels may be due to running lean, but my question is what would cause a stock motor (basically) to run lean and if so how can i make it rich without installing a fpr or something
in regards to timing i had already retarded it to 14btdc from 16btdc.
new plugs/wires/dist cap/rotor
fresh oil change
running 87 octane and i boned out hard right before the smog test
my car doesn't overheat
i need somebody to tell me what the problems can be so i can get my tags renewed
edit i dont know if this will help but let's see.. if i turn off my car then try to turn it back on within like 5 seconds or so it will start up but then stall out.
Modified by jerbear! at 10:05 PM 2/27/2006
02-26-2006, 04:53 PM
#3
Honda-Tech Member
Join Date: Oct 2004
Location: CA
Posts: 1,068
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (jerbear!)
Actually NoX is not necessarily caused by a lean condition but actually from the combustion chamber being too hot. Nox forms at like 2500 degress F. When your motor leans out then the combustion gets hotter.
Also to answer your question usually when you want to richen up your fuel mixture you need to use a different ecu. Maybe because you are using a different cam your not getting enough fuel. Maybe you should try a p28?
Also to answer your question usually when you want to richen up your fuel mixture you need to use a different ecu. Maybe because you are using a different cam your not getting enough fuel. Maybe you should try a p28?
02-26-2006, 06:29 PM
#4
Honda-Tech Member
Thread Starter
Join Date: Jan 2003
Location: SO CAL, ca, us
Posts: 1,567
Likes: 0
Received 0 Likes
on
0 Posts
although my timing reads at 14 btdc, since i have an adjustable cam gear.. the timing for the gear is still advanced, would retarding the cam gear or making it to tdc make the timing too retarded? or is it worth a try.
02-27-2006, 01:10 AM
#6
Honda-Tech Member
Thread Starter
Join Date: Jan 2003
Location: SO CAL, ca, us
Posts: 1,567
Likes: 0
Received 0 Likes
on
0 Posts
Re: (hazw8st)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hazw8st »</TD></TR><TR><TD CLASS="quote">How is the relative condition of the engine? Filters? Fuel pump? Because your engine might be starving of fuel.</TD></TR></TABLE>
engine is fine. has 130k on it and had timing belt/water pump/thermostat/fuel filter and all that good stuff done at 100K when i first bought the car.
how can the motor be starving of fuel if it is stock?
engine is fine. has 130k on it and had timing belt/water pump/thermostat/fuel filter and all that good stuff done at 100K when i first bought the car.
how can the motor be starving of fuel if it is stock?
Trending Topics
02-27-2006, 01:24 AM
#8
Honda-Tech Member
Join Date: Mar 2004
Location: Pinole, CA, United States
Posts: 244
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (jerbear!)
I had a similar problem when i smogged my b16 a few months back. I had adjustable cam gears and had them set at aroun 4 degrees (dont ask why), I tuned them to 0 degrees and changed my O2 sensor (which was bad) and passed perfectly. Try the cam degree setting, and if that doesn't work consider getting a new O2 sensor, I got a used one from a junk yard for cheap and it worked. Good luck.
02-27-2006, 01:43 AM
#9
Honda-Tech Member
Thread Starter
Join Date: Jan 2003
Location: SO CAL, ca, us
Posts: 1,567
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (sagron69)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sagron69 »</TD></TR><TR><TD CLASS="quote">I had a similar problem when i smogged my b16 a few months back. I had adjustable cam gears and had them set at aroun 4 degrees (dont ask why), I tuned them to 0 degrees and changed my O2 sensor (which was bad) and passed perfectly. Try the cam degree setting, and if that doesn't work consider getting a new O2 sensor, I got a used one from a junk yard for cheap and it worked. Good luck.</TD></TR></TABLE>
the smog center marked me as 14 btdc however my gear timing is still 2 degrees advanced.. should i set my gear timing to 0 or maybe even slightly retard?
the smog center marked me as 14 btdc however my gear timing is still 2 degrees advanced.. should i set my gear timing to 0 or maybe even slightly retard?
02-27-2006, 01:57 AM
#10
Honda-Tech Member
Join Date: Mar 2004
Location: Pinole, CA, United States
Posts: 244
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (jerbear!)
Set it to 0 degrees, the d16 cam at 0 degrees should be as close to stock as you can hope for. This is all trial and error, it worked for me and may also work for you. If setting the degrees to 0 doesn't help try replacing the O2 sensor or furtherly retarding the cam gear.
Also, when you are running the car on the smog dyno, is it fully warmed up or slightly cold?
Also, when you are running the car on the smog dyno, is it fully warmed up or slightly cold?
02-27-2006, 02:37 AM
#11
Honda-Tech Member
Thread Starter
Join Date: Jan 2003
Location: SO CAL, ca, us
Posts: 1,567
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (sagron69)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sagron69 »</TD></TR><TR><TD CLASS="quote">Set it to 0 degrees, the d16 cam at 0 degrees should be as close to stock as you can hope for. This is all trial and error, it worked for me and may also work for you. If setting the degrees to 0 doesn't help try replacing the O2 sensor or furtherly retarding the cam gear.
Also, when you are running the car on the smog dyno, is it fully warmed up or slightly cold?</TD></TR></TABLE>
i have a d16a6 cam which requires to have an adjustable cam gear since the cam will make your belt off a couple teeth. nevertheless i'll try setting the gear itself to 0.
also, the car was fully warmed up and im sure the cat was too due to my spirited drive one minute before the smog test.
about the o2 sensor, i replaced my o2 sensor with my other civic which has a newer sensor on and i still failed.
Also, when you are running the car on the smog dyno, is it fully warmed up or slightly cold?</TD></TR></TABLE>
i have a d16a6 cam which requires to have an adjustable cam gear since the cam will make your belt off a couple teeth. nevertheless i'll try setting the gear itself to 0.
also, the car was fully warmed up and im sure the cat was too due to my spirited drive one minute before the smog test.
about the o2 sensor, i replaced my o2 sensor with my other civic which has a newer sensor on and i still failed.
02-27-2006, 07:43 AM
#12
Honda-Tech Member
Join Date: Jul 2005
Location: United States
Posts: 435
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (jerbear!)
I am very close to passing right now, my HC was 2 points above at 25mph, on my last ref visit. But, when my NOX was high, I talked to this smog station repair guy and he was kind enough to give me this info.
Just because the car doesn't overheat, doesn't mean it's not running too hot. His suggestions were:
- Lower temp thermostat (I got a Spoon Sports one)
- Platinum Spark plugs (I put NGK Iridium ones)
I also put in some Redline Watter Wetter, to make sure thet coolant is working as hard as it can.
These things worked for me. They brought my NOX down from 782 to 225. They are not cheap, but they are not throwaway items after smog. Of course, this is assuming you have a functional cat and the rest of your emissions system is up to spec.
Just because the car doesn't overheat, doesn't mean it's not running too hot. His suggestions were:
- Lower temp thermostat (I got a Spoon Sports one)
- Platinum Spark plugs (I put NGK Iridium ones)
I also put in some Redline Watter Wetter, to make sure thet coolant is working as hard as it can.
These things worked for me. They brought my NOX down from 782 to 225. They are not cheap, but they are not throwaway items after smog. Of course, this is assuming you have a functional cat and the rest of your emissions system is up to spec.
02-27-2006, 07:54 AM
#13
Honda-Tech Member
Join Date: Aug 2005
Location: seattle, wa, usa
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (EG6_GUY)
sounds like fuel starve. fuel isnt only combustable. it also helps to cool the delivery system. a new ECU is a must when doing any swap. and a fpr for 140 bucks is worth it when doing anything to make your car faster.
02-27-2006, 08:35 AM
#14
Honda-Tech Member
Join Date: Dec 2005
Posts: 1,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (imskatencrzy)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by imskatencrzy »</TD></TR><TR><TD CLASS="quote">sounds like fuel starve. fuel isnt only combustable. it also helps to cool the delivery system. a new ECU is a must when doing any swap. and a fpr for 140 bucks is worth it when doing anything to make your car faster.</TD></TR></TABLE>
So many people overlook that in their swaps.
So many people overlook that in their swaps.
02-27-2006, 08:38 AM
#15
Mr. Badwrench
Join Date: May 2002
Location: stranger in a strange land
Posts: 14,146
Likes: 0
Received 2 Likes
on
2 Posts
Re: smog failed nox (JeffBro)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JeffBro »</TD></TR><TR><TD CLASS="quote">Actually NoX is not necessarily caused by a lean condition but actually from the combustion chamber being too hot. Nox forms at like 2500 degress F. When your motor leans out then the combustion gets hotter.
Also to answer your question usually when you want to richen up your fuel mixture you need to use a different ecu. Maybe because you are using a different cam your not getting enough fuel. Maybe you should try a p28?</TD></TR></TABLE>
also make sure your cam gear is straight up, and put your timming to stock.
Also to answer your question usually when you want to richen up your fuel mixture you need to use a different ecu. Maybe because you are using a different cam your not getting enough fuel. Maybe you should try a p28?</TD></TR></TABLE>
also make sure your cam gear is straight up, and put your timming to stock.
02-27-2006, 12:02 PM
#17
Honda-Tech Member
Join Date: Dec 2005
Posts: 1,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: (jerbear!)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jerbear! »</TD></TR><TR><TD CLASS="quote">nox @ 15mph = 189
nox @ 25mph = 1731
does that help?</TD></TR></TABLE>
Damn. High combustion temperatures.....
nox @ 25mph = 1731
does that help?</TD></TR></TABLE>
Damn. High combustion temperatures.....
02-27-2006, 12:19 PM
#18
Honda-Tech Member
Re: smog failed nox (JeffBro)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JeffBro »</TD></TR><TR><TD CLASS="quote">Actually NoX is not necessarily caused by a lean condition but actually from the combustion chamber being too hot. Nox forms at like 2500 degress F. When your motor leans out then the combustion gets hotter.
Also to answer your question usually when you want to richen up your fuel mixture you need to use a different ecu. Maybe because you are using a different cam your not getting enough fuel. Maybe you should try a p28?</TD></TR></TABLE>
look at what you wrote. lean conditions cause the combustion temps to go up. rich conditions cools the temperature. how does the combustion chamber get hot?it could be a clogged fuel filter and timing, put everything back to zero
Also to answer your question usually when you want to richen up your fuel mixture you need to use a different ecu. Maybe because you are using a different cam your not getting enough fuel. Maybe you should try a p28?</TD></TR></TABLE>
look at what you wrote. lean conditions cause the combustion temps to go up. rich conditions cools the temperature. how does the combustion chamber get hot?it could be a clogged fuel filter and timing, put everything back to zero
02-27-2006, 01:02 PM
#19
Honda-Tech Member
Thread Starter
Join Date: Jan 2003
Location: SO CAL, ca, us
Posts: 1,567
Likes: 0
Received 0 Likes
on
0 Posts
Re: (hazw8st)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hazw8st »</TD></TR><TR><TD CLASS="quote">
Damn. High combustion temperatures.....</TD></TR></TABLE>
it was worse before
before i got my new cat, nox @ 15mph and 25mph = 2700!
now that i changed my cat and retarded the ignition timing to 14btdc im getting 189 and 1731
Damn. High combustion temperatures.....</TD></TR></TABLE>
it was worse before
before i got my new cat, nox @ 15mph and 25mph = 2700!
now that i changed my cat and retarded the ignition timing to 14btdc im getting 189 and 1731
02-27-2006, 01:03 PM
#20
Honda-Tech Member
Thread Starter
Join Date: Jan 2003
Location: SO CAL, ca, us
Posts: 1,567
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (fmrprojects)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fmrprojects »</TD></TR><TR><TD CLASS="quote">
look at what you wrote. lean conditions cause the combustion temps to go up. rich conditions cools the temperature. how does the combustion chamber get hot?it could be a clogged fuel filter and timing, put everything back to zero
</TD></TR></TABLE>
what are signs of a clogged fuel filter?
look at what you wrote. lean conditions cause the combustion temps to go up. rich conditions cools the temperature. how does the combustion chamber get hot?it could be a clogged fuel filter and timing, put everything back to zero
</TD></TR></TABLE>
what are signs of a clogged fuel filter?
02-27-2006, 03:56 PM
#21
Honda-Tech Member
Join Date: Dec 2005
Posts: 1,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: smog failed nox (jerbear!)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jerbear! »</TD></TR><TR><TD CLASS="quote">
what are signs of a clogged fuel filter?
</TD></TR></TABLE>
Fuel filters are easy and inexpensive to exchange. I have always installed fuel pressure gages in my whips.
what are signs of a clogged fuel filter?
</TD></TR></TABLE>
Fuel filters are easy and inexpensive to exchange. I have always installed fuel pressure gages in my whips.
03-01-2006, 01:18 PM
#25
Honda-Tech Member
Join Date: Dec 2005
Posts: 1,214
Likes: 0
Received 0 Likes
on
0 Posts
Re: (jerbear!)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jerbear! »</TD></TR><TR><TD CLASS="quote">bump in the booty</TD></TR></TABLE> Yeah! Lil Jon kinda voice!