hatch_

its a 94 dx. everything is completely stock.


i have no idea of why it didnt pass. i just barely got a new catalytic converter for it too. anyone have any ideas?

Ya Digg

get SEAFOAM https://honda-tech.com/zerothread?id=1502112

Mr.EM1_EK

yeah clean your **** out. do a tune up

Crazydave

Your car failed because your hydrocarbons (HC) and Carbon Monoxide (CO) are too high.

see the website below for some possible solutions:

http://www.artsautomotive.com/thesmogstory.htm


and

http://www.troublecodes.net/articles/smog.shtml


and

http://www.aeswave.com/new/www...2.pdf


Modified by Crazydave at 4:10 PM 4/24/2007

Ya Digg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.EM1_EK &raquo;</TD></TR><TR><TD CLASS="quote">yeah clean your **** out. do a tune up</TD></TR></TABLE>

X2

deadline

do u have a CAT ?

SOHCEK-Turbo

iTrader: (1)

Change Cat and do mild tune up. Spark plgs, oil change, check your wires.....

Seems you are running rich.

Jhonny Ricer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by deadline &raquo;</TD></TR><TR><TD CLASS="quote">do u have a CAT ?</TD></TR></TABLE>
Did he not say it was completely stock?
And for those telling him to get a new cat he stated he just replaced it read before you reply.

SOEX

One thing that I always do is make sure that cat is nice and hot. Run the car really hard for a while. It helps some. Good luck, our state is tough on smog.

EvilPhu

Look like an O2 sensor for me, get a meter and tap the signal of the O2, and ground the other end. Watch the voltage move back and forward.

dtapia

the nox is extreamly high and could be a o2.
here is some food for thought.

NOx: The Know-How You Should Know Now
For many areas of the country, NOx testing has (or
will) become a major part of vehicle emissions
testing. You can be sure that customers whose
vehicles fail the test due to high NOx levels will be
coming to your shop with questions. So even if you
don’t have NOx testing equipment, you need to know
what NOx is, what causes it, and how to reduce it.
What is NOx?
NOx (oxides of nitrogen) is a product of nitrogen and
oxygen combining at high, sustained temperatures
(2,500°F or more) inside the engine’s combustion
chambers. NOx becomes a problem when it mixes
with hydrocarbons (unburned fuel vapor) in the lower
atmosphere and forms that brown haze most of us are
all too familiar with: smog.
What Causes NOx?
Many factors are involved in NOx production. High,
sustained combustion temperature is just one. Here
are some others:
Engine ping: Plain and simple, if the engine
detonates (pings), it’s producing excessive NOx. As
a general rule, if you correct the detonation, you fix
the NOx problem.
Over-advanced ignition timing: This causes
detonation, so it’s a related cause of excessive NOx.
Over-advanced timing creates an early buildup of
combustion chamber pressure because the spark
plugs fire too soon in the compression stroke. The
still-increasing pressure ignites a secondary flame
front inside the chamber that collides with the flame
front of normal combustion. The collision of these
flame fronts is the “ping.”
Lean mixture: A lean mixture causes a higher than
normal temperature in the intake air/fuel mixture,
causing the preignition that produces high NOx.
Any condition that makes the engine run lean may
increase NOx.
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
MOST EFFICIENT
AIR/FUEL RANGE
10:1
NOx levels are mostly affected by combustion temperature, but
they also tend to vary with mixture levels.
MIXTURE
15:1 20:1
Rich mixture: A richer than normal mixture won’t
increase NOx, but the high CO (carbon monoxide) it
creates will mask excessive NOx. Before you check
the NOx reading, lower the CO level by correcting
the mixture.
Carbon deposits: If hot carbon deposits ignite the
mixture before normal combustion begins, the
resulting flame front collides with the flame front of
normal combustion. The noise of this collision is
preignition, and preignition causes excessive NOx.
Low-octane fuel: Low-octane fuel is more likely to
detonate than high-octane fuel. If you use a fuel
with a lower than recommended octane level, it can
cause the detonation that produces NOx.
Fuel injectors: The altered spray patterns of dirty
injectors can create hot spots in combustion
chambers that increase NOx. A dirty injector causes
more NOx because it increases the combustion
chamber temperature. And dirty injectors reduce the
NOx-lowering capability of the catalytic converter
because they increase the oxygen in the exhaust.
NOx Control
A vehicle’s emissions control system reduces NOx
two ways: during precombustion with EGR (exhaust
gas recirculation), and during post- combustion with
the TWC (three-way catalytic converter). By injecting
a small amount of exhaust gas into the intake stream,
EGR reduces NOx by lowering the temperature of
combustion. The TWC then uses a reduction method
to lower NOx even more. (The TWC also lowers HC
[hydrocarbons] and CO levels through oxidation.)
When it leaves the tailpipe, most of the exhaust gas
has been converted to water vapor and carbon
dioxide. On a healthy engine under load, the NOx
level out of the tailpipe should be 200 to 600 PPM
(parts per million).
How to Reduce NOx
To reduce NOx on a vehicle that fails an emissions
test, do these 10 steps, in order:
1. Check the timing, and make sure it’s within
specification.
2. Make sure the knock sensor and its circuit are
working. A malfunctioning sensor can cause
over-advanced timing.
3. Check the EGR system. Look for correct vacuum
to the EGR valve and proper valve operation.
4. If needed, clear any clogged EGR passages.
5. Make sure the octane rating of the fuel being used
is high enough for the engine.
6. Check the coolant, and add some if needed.
7. Check the cooling system (thermostat, cooling
fan, fan clutch, etc.) for proper operation. If any of
these parts aren’t working, they’ll cause excessive
NOx from an overheated engine or high intake air
temperature.
8. Check for dirty or clogged fuel injectors, and
clean or replace them as needed.
9. Check the O2 sensor reading(s) for an overly lean
mixture, and correct the mixture if needed.
10. If the previous steps didn’t reduce the NOx level,
use a decarbonizer to remove carbon buildup in
the combustion chambers.

dtapia

forgot to ask when is the last time the oil was changed have seen many cars fail over a oil change ? one of the simplist things to over look.

Vsm Hatch

I'm having the same problem. My numbers are really similar to that. NOX isn't over limit but is at the same range. HC and CO are up. Would your explaination of NOX being high be part of the problem since NOX isn't over limit? I'm waiting on new O2 sensors in case they are the problems right now, but I'm still trying to narrow down the problem. Wouldn't the knock sensor pull timing if it sense false readings?

What level octane should be used in a GSR motor to lower HC and CO? Would using normal oil versus synthetic be good in case blowby is increasing HC and CO?

ph

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.EM1_EK &raquo;</TD></TR><TR><TD CLASS="quote">yeah clean your **** out. do a tune up</TD></TR></TABLE>

already did.