STOLEN - ITR 98-0652

Ok, so I took my car to get smogged today and it failed.

Here are the readings (bear with my attempts to format it):

%co2 %02 hc (ppm)
test rpm meas meas max ave meas
15mph 2207 14.69 0.11 61 9 99
25mph 2442 14.80 0.01 45 7 45


co (%) no (ppm)
test rpm max ave meas max ave meas
15mph 2207 0.54 0.02 0.16 467 57 376
25mph 2442 0.53 0.03 0.08 754 50 83

So here's my story... freshly tuned up (plugs, wires, cap, rotor, valve adjustment, ignition timing, clean k&n, etc.). I have historically burned a bit of oil (old plugs had a small amount of white speckled residue - oil ash according to some, within normal residue according to others). The smog tech didn't think it was a rich/lean issue due to the %co2 and co(%) numbers. I figure the only way for hydrocarbons to get into the combustion chamber is via fuel or via oil, right?

As you can see, the "hc (ppm)" is WAY out of spec and it barely passed at the 25mph load. I have added some "pass or don't pay" cleaner that showed some before and after pics of pistons and combuston chamber residue...

So, how do I fix it so it will pass? Any thoughts?

Denny

i think hydrocarbons is due to your cat. but im a retard so maybe im wrong

STOLEN - ITR 98-0652

Ok, anyone want to loan me a cat for a day?

The tech said the co2% was an indicator of cat efficiency. I have no codes to indicate the cat is out - both 02 sensors on line.

B20Monster

your emission readings arent too bad.. it would help a lot if you had the car running at about 2,500 rpm 2-3 mins before the tech runs the car on the dyno. i've seen many readings like that. .. and for the most part, that's what i usually do and the car passes after.

cruzersi99

AGreed. Get the cat hot.

Do you have any other aftermarket parts on the car? Cams, tuning, etc.?

Cruzer

STOLEN - ITR 98-0652

Parts:

Mugen 4-1 (USDM), Mugen Twin-Loop (Big Ol' Dent in Resonator ), Cam Gears (Currently at 0,0), AEM CAI (just for the noise, I guess), and Unorthodox Pulley. Nothing that would really bump HCs since fuel delivery is unaffected.

I'm guessing for the $15 to test again, I'll give it a shot post-detergent with a hot-hot kitty. Timing is key, since I don't want the car to cool while I'm waiting to be serviced...

EFSiR

just make sure that the fan is blowing over your cat . If it get's too hot, it's not working...
HTH

eg_type_r93

high hc means you are running to lean (high combustion chamber temp.) this will cause a high lever of hc due to the extreme heat just a by - product of combustion.

look you modified air into and out of the motor with out thinking about fuel that thing is running lean 100% for sure get a fuel pressure regulator

STOLEN - ITR 98-0652

Ok, other than the "cold start enrichment" from the ECU, how can I get more fuel in there? No VAFC or Hondata, unfortunately. How about colder plugs (more heat transfer to head and away)?

Cat too cold? Combustion Chamber too hot? What the frell?

RotaryBzzzz

looks like a dying cat to me. How old is your oil? I try and smog w/in 50 miles of an oil change.

Run some high octane fuel...run the shiet out of your car on the freeway before you test...leave it idling right when you pull up...see my sig

STOLEN - ITR 98-0652

Do I have any more votes for a bad kitty?

STOLEN - ITR 98-0652

It was brought to my attention that the engine speeds are quite low (thanks 98R-1144 ). It looks like 15mph was done in 2nd gear and 25mph was done in 3rd gear.

Does that seem absurd to anyone else?

Ya think I could get the *next* tech to do it in 1st and 2nd gear, respectively? I reckon I'd pass at 3000+ rpm, eh?

b19coupe

There are rpm limits, the machine won't test above a certain rpm. Keeping a vehicle in the speed/rpm range for the duration of the test can be a pain; the machine will kick you out of the test for exceeding the limits too much. As stated above, drive the **** out of the car right before the test to heat up the cat, and don't let it cool too much, if you can help it. HC's, BTW ,are just unburned fuel-the result of a misfire. High CO is an indication of a rich mixture (incomplete combustion), and NOX is the result of high combustion chamber pressures and temperatures.

93SSPHatch

I just took my CA smog test today as well, and I failed for a GSR

Here are my results:

15mph- HC = 89max 184 meas // NO = 708max 1451meas
25mph- HC = 54max 54meas // NO = 746max 44meas

I have a JDM GSR with AEM CAI, Walbro 190lph fuel pump, and Carsound High Flow Cat (six months old).

In a sense we are both in the same boat. The smog ref said that if I fixed my high HC levels, my NO levels would also drop. I was able to sneak my VAFC into the test, and I leaned out the entire mixture -20% across the entire narrow/wide throttle range. Now that I have finished reading this thread, I saw someone mention that running lean doesn't help, but running richer is the key to passing; any one else have thoughts?

b19coupe

Too lean-combustion chamber temps go up, NOX goes up. You can also have a lean misfire, which equals high HC's. Too rich, CO goes up.

irev210

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg_type_r93 &raquo;</TD></TR><TR><TD CLASS="quote">high hc means you are running to lean (high combustion chamber temp.) this will cause a high lever of hc due to the extreme heat just a by - product of combustion.

look you modified air into and out of the motor with out thinking about fuel that thing is running lean 100% for sure get a fuel pressure regulator </TD></TR></TABLE>

you are very wrong. high HC means unburnt fuel, high combustion chamber temp (over 2500 degrees F = high NOx)

i'd put a new cat on there, and make sure your car is very hot before going on the dyno again.

irev210

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">Too lean-combustion chamber temps go up, NOX goes up. You can also have a lean misfire, which equals high HC's. Too rich, CO goes up.</TD></TR></TABLE>


this guy knows whats up

STOLEN - ITR 98-0652

Right, right... The origins of the various noxious gases seems settled.

So, if I'm getting the salient points summarized...

(1) Drive the **** out of it and test it hot.
(2) To avoid any misfire or a potential weak spark plug, I'll replace them. (Gap at min spec.)
(3) I'll even try high octane gas (can't hurt, eh?)
(4) Eventually, I'll have to replace the kitty.


Wish me luck.

apexi

Also check your fuel pressuer regulator. You are probably running way rich. Too much fuel can also cause high HC reading.

DRFlickner

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITR 98-0652 &raquo;</TD></TR><TR><TD CLASS="quote">
(3) I'll even try high octane gas (can't hurt, eh?)
Wish me luck.</TD></TR></TABLE>

Wouldn't too high of octane leave unburnt fuel as well? Good luck w/ your smog! Hopefully you can get away w/o buying a new cat.

RotaryBzzzz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">Too lean-combustion chamber temps go up, NOX goes up. You can also have a lean misfire, which equals high HC's. Too rich, CO goes up.</TD></TR></TABLE>

You are right.

RotaryBzzzz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by irev210 &raquo;</TD></TR><TR><TD CLASS="quote">

you are very wrong. high HC means unburnt fuel, high combustion chamber temp (over 2500 degrees F = high NOx)</TD></TR></TABLE>


You are thinking right but applying wrong situationally.