failed emmissions, HC's too high
09-27-2004, 07:27 PM
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failed emmissions, HC's too high Well, I went in today and did my emmissions and like the title says I Failed. at idle my HC PPM was 805 CO was .88. At 2500 RPM my HC PPM was 462 and the CO was 1.02. The limits were 220.0 for HC's and 1.2 for CO's. I have no emmissions equipment. Can I get through emmissions with just ls1edit tuning??
Anyone have any idea what's going on? Help would be much appreciated.
Anyone have any idea what's going on? Help would be much appreciated.
09-27-2004, 07:33 PM
#2
Get the car tuned, turn the timing back, turn your boost as low as you can go, and get the A/F up around 13.5 or so. It should pass, the hydrocarbons have to do with the A/F of the car. You're probably tuned to be at 11.5 or so, that's gonna fail for sure. Just turn everything down, go thru, nad then turn it back up and restore your currnet tune. You gotta have cat's on the car too, if you don't, get one put in with a nice ball coupling on both ends, and have a strait pipe on made that fits in it's placesomewhere as close to the motor as you can in the downpipe. The cat has to get hot enough to work, so the closer to the motor it is, the better. Do that, and yo should be good to go.
09-27-2004, 08:01 PM
#3
Do they do OBDII testing? In MO if it fails the OBDII scan they'll throw it on the dyno. If thats how its done the best way to tackle the problem is eliminate all possible codes that are being thrown. Make sure all systems such as the egr are turned on, even if its not there, set all the egr values to 0. Make sure the o2 is in ready mode ect. With proper tuning you can make obdII believe its all correct no matter how bad it pollutes 
and you'll avoid haivng to dyno it and getting a real exhaust reading
and you'll avoid haivng to dyno it and getting a real exhaust reading
09-27-2004, 09:53 PM
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Larimer county emmissions are not enhanced, so I don't have to get on the rolkers. It's just a gas analyzer testing two values. They don't even plug OBDII in. Is high HC's a rich or lean condition. The guy there told me it's a lean condition. He also told me to back the timing down a little.
09-28-2004, 09:10 AM
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HCs come in at both too-rich and too-lean operation.
CO is too rich, NOx is too lean. The combination should
give you a pointer. HC also comes from misfires. On a
'98 I would suspect some funny things out of !EGR and
high spark advance in the "EGR active" region if this has
not been programmed away.
For emissions you might want a special program that
maintains stoich to as high a power level as possible,
this would want you to really ease up on the boost and
delay PE mode as long as you can (how high do they
rev the motor on the gas analyzer anyway?).
Change your oil, too, blowby loading elevates HC emissions.
CO is too rich, NOx is too lean. The combination should
give you a pointer. HC also comes from misfires. On a
'98 I would suspect some funny things out of !EGR and
high spark advance in the "EGR active" region if this has
not been programmed away.
For emissions you might want a special program that
maintains stoich to as high a power level as possible,
this would want you to really ease up on the boost and
delay PE mode as long as you can (how high do they
rev the motor on the gas analyzer anyway?).
Change your oil, too, blowby loading elevates HC emissions.
09-28-2004, 03:09 PM
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Originally Posted by jimmyblue
HCs come in at both too-rich and too-lean operation.
CO is too rich, NOx is too lean. The combination should
give you a pointer. HC also comes from misfires. On a
'98 I would suspect some funny things out of !EGR and
high spark advance in the "EGR active" region if this has
not been programmed away.
For emissions you might want a special program that
maintains stoich to as high a power level as possible,
this would want you to really ease up on the boost and
delay PE mode as long as you can (how high do they
rev the motor on the gas analyzer anyway?).
Change your oil, too, blowby loading elevates HC emissions.
CO is too rich, NOx is too lean. The combination should
give you a pointer. HC also comes from misfires. On a
'98 I would suspect some funny things out of !EGR and
high spark advance in the "EGR active" region if this has
not been programmed away.
For emissions you might want a special program that
maintains stoich to as high a power level as possible,
this would want you to really ease up on the boost and
delay PE mode as long as you can (how high do they
rev the motor on the gas analyzer anyway?).
Change your oil, too, blowby loading elevates HC emissions.
In Larimer county Colorado they only do idle and 2500 rpm gas analyzer readouts. I have a slight misfire, my idle ignition values are stock and I don't have EGR anymore. An oil change is due so I will do that. How much should I decrease my ignition by? I believe it's 27 degrees at idle in the high octane table.
09-28-2004, 04:15 PM
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There is an EGR adder table that throws down some
extra when the EGR is expected on. I would leave
the main table alone, and just zero the EGR adder.
You might want to log misfire current PIDs at the
two RPM levels and check that you do not have
any particularly troublesome cylinders that stand out.
One other thing occurs to me, there are some
"proportional O2" params I see in HPTuners, on the
HPTuners site some of the guys were discussing
these and how they would (if set right) minimize
the O2s overshoot; for emissions you would like
to maintain an even keel, not swing rich-lean-rich
all the time (the gas analyzer then gets to see a
soup of rich products and lean products, rather
than a clean burn stream from an ideal mix). This
might help you out if you could get it right.
If you have headers you might want to put on a
fresh pair of front O2s - and take them back off
right away, for next year.
extra when the EGR is expected on. I would leave
the main table alone, and just zero the EGR adder.
You might want to log misfire current PIDs at the
two RPM levels and check that you do not have
any particularly troublesome cylinders that stand out.
One other thing occurs to me, there are some
"proportional O2" params I see in HPTuners, on the
HPTuners site some of the guys were discussing
these and how they would (if set right) minimize
the O2s overshoot; for emissions you would like
to maintain an even keel, not swing rich-lean-rich
all the time (the gas analyzer then gets to see a
soup of rich products and lean products, rather
than a clean burn stream from an ideal mix). This
might help you out if you could get it right.
If you have headers you might want to put on a
fresh pair of front O2s - and take them back off
right away, for next year.
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09-28-2004, 04:34 PM
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Originally Posted by jimmyblue
There is an EGR adder table that throws down some
extra when the EGR is expected on. I would leave
the main table alone, and just zero the EGR adder.
You might want to log misfire current PIDs at the
two RPM levels and check that you do not have
any particularly troublesome cylinders that stand out.
If you have headers you might want to put on a
fresh pair of front O2s - and take them back off
right away, for next year.
extra when the EGR is expected on. I would leave
the main table alone, and just zero the EGR adder.
You might want to log misfire current PIDs at the
two RPM levels and check that you do not have
any particularly troublesome cylinders that stand out.
If you have headers you might want to put on a
fresh pair of front O2s - and take them back off
right away, for next year.
09-28-2004, 05:07 PM
#9
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Don't know about Edit; in HPTuners next to the
High/Low Octane tables, there are several spark
correction tables for IAT, ECT, EGR, etc; figure
Edit ought to be arranged similarly but that's just
a guess.
High/Low Octane tables, there are several spark
correction tables for IAT, ECT, EGR, etc; figure
Edit ought to be arranged similarly but that's just
a guess.
09-28-2004, 05:14 PM
#10
TECH Senior Member
i just checked my ls1 edit 1.3 copy and don't see the EGR timeing advance add table... there's an ECT, and IAT and that seems to be it... i only looked briefly but didn't see it anywhere i would think it should be
10-01-2004, 10:51 PM
#12
Originally Posted by 98TurboZ
Well, I went in today and did my emmissions and like the title says I Failed. at idle my HC PPM was 805 CO was .88. At 2500 RPM my HC PPM was 462 and the CO was 1.02. The limits were 220.0 for HC's and 1.2 for CO's. I have no emmissions equipment. Can I get through emmissions with just ls1edit tuning??
Anyone have any idea what's going on? Help would be much appreciated.
Anyone have any idea what's going on? Help would be much appreciated.
800 RWHP, 753RWTQ, Passed ODBII test.
The key is when they are performing your test, they start the car, and let it sit and idle to bring the car up to normal operating temperature.
Regardless of what kind of setup you have, idle is idle. use your tuning software and a wideband O2, and set the idle fuel cells in the MAIN VE which should be in the 45-60 Kpa range around 800-1200 rpm to be at 14.7 to 1 AFR, and your emissions passing test problem will go away. It is that simple.
If you do not have cats on your car, you have to do one of two things, Nothing will get you around a tailpipe test, unless you have the a/f at 14.7 to 1. But if you need to pass a physical inspection, you can get real cats, but you need to keep the a/f in the upper 12's to lower 13's in order not to burn the cats up. Too much fuel in the Cat and a lot of HP can cause a fire. "Quoted from Random Flow", The rumor about keeping the low a/f or running rich when using a cat, is misinformation. A rich condition on a High HP car with CATS will cause a fire.
Option two, and you are on your on with this one, hollow out the cats, and install o2 sims in the rear. The computer will never know the difference. Keeping the idle at 14.7 to 1, will pass if they ask for the tail pipe test.
A/F Ratio has nothing to do with power. It takes a very small amount of fuel to create cumbustion. The extra fuel is used in the cylinder to cool the chamber and control the heat generated from the explosion. Ignition timing is the key to making power. Where the pision is in relation to when the spark happens.
You will not hurt anything by running your idle at 14.7 to 1. The car is not under any kind of load.
Hope this helps. NC uses the ODBII test. If you fail that you move on to the tail pipe test. If you have to do the dyno test, you have to get it as close to 14.7 to 1 without melting something, especially on a blower car, and reduce the timing as far down as possible.
Hope that helps
Bryan
