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Failed Smog, high HC; Idle speed Hydrocarbons too high
Topic Started: Oct 8 2013, 01:29 AM (1,552 Views)
Flash
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53 mpg last trip

Hey, anyone, I need some help.

Went to smog my '92 Metro Yesterday.....it failed.

I changed out my OX sensor today, hoping it helps, and bought some Lucas fuel injector cleaner.

The engine is fully rebuilt with: new .020 over pistons, 3Tech econo head & cam w/ 6 deg advance timing gear. New pcv, plugs, etc.
Motor has about 160 miles on it. Runs good. Starts after 1 - 2 seconds of cranking.

Engine idles at 850 rpm. Set timing at 4-5 BTDC, (jumped out that plug ).

Max allowed HC, at idle, is 220 ppm, mine blew a 234. I don't know what the other results were because Nevada has a rule that if it passes,
they wont tell what the results were, and if it fails they only show what failed....nothing else.

I would think the econo cam would help it pass.
Does having a 6 deg timing gear affect SMOG?

On my '85 Nissan truck, if I retard the ignition past TDC it will pass SMOG.
Is it the same for Metros???

Before the rebuild it would pass, and that was with it using a quart of oil every 300 miles. :ermm:

Anyone have an idea of what I could do?
Thanks.
Edited by Flash, Oct 8 2013, 09:22 PM.
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Flash
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53 mpg last trip

Anyone?
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David95237


The o2 sensor may do it for you the oil burning may have don your cat in also. Put a gallon of e85 in the tank will nock it a few points.
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Deleted User
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Put on a new catalytic converter.
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Woodie
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Advancing the ignition timing should reduce HC, but it will increase NOx.
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calrenman
Just another wrench.

Glen got it possibly. There is a program that you can plug the values of your test and it will diagnose the problem. I just cannot remember the name. I had a problem with my toyota truck. It turned out to be HCs and it was a dead cat. Advance it to within a degree below the "legal" limit spec. and you might get lucky. I would search out that computer program.

Where were your NOX? That will rise as previously stated.
Edited by calrenman, Oct 9 2013, 08:58 AM.
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calrenman
Just another wrench.

Geo Glenn
Oct 8 2013, 09:36 PM
Put on a new catalytic converter.
:gp
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gbreadman
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Tinkerer

The o2 sensor will drop it very quickly. New cat will also lower it since the catalysts are probably gummed up by now with soot.

NOx can be dropped to near zero with a three-way cat, coolant flush, and egr cleaning; hot engine and high compression is what raises that.
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Papa_G
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[ *  *  * ]
One thing I learned as a smog tech back in the day was that the cat had to be HOT before a test to pass properly. That was back when cats were a fairly new tech, and we were still using BAR machines with sniffer wands. I also found this to be true of today's OBD1 and II cars. If you just start up and drive less than 20 minutes to the smog station, and it's marginal to begin with, it ain't gonna pass. Drive it for 30 to 45 minutes before taking it in and get the cat hot. You're not that far off.

P.S. Did you put the old plugs back in it, or did you put new ones in?
Edited by Papa_G, Oct 11 2013, 01:43 AM.
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calrenman
Just another wrench.

Did it pass?
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Flash
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53 mpg last trip

Yes, I got it to pass. :rocker :banana


I installed a new OX sensor, and poured in a bottle of Lucus fuel injector cleaner, and drove it over 100 miles.
I also disconnected my "warm air" intake, and retarded the timing a little.

It passed, but I have no idea by how much, due to stupid S.Nevada smog laws. :banghead
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