best spark plugs and gas for smog check?

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CAR DUDE - 18 May 2004 04:40 GMT

Yo dudes! I'm trying to pass the smog check. Man I failed the last time. I
got low readings for HC and CO but high readings for NO levels. What could
it be? Will changing spark plugs help? What would be the best types of
spark plugs? What about gas? I was using regular unleaded gas that was
sitting in the car for nearly a year. Does that matter?

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Daniel J. Stern - 18 May 2004 05:57 GMT

> Yo dudes! I'm trying to pass the smog check. Man I failed the last time.
> I got low readings for HC and CO but high readings for NO levels. What
> could it be? Will changing spark plugs help? What would be the best
> types of spark plugs? What about gas? I was using regular unleaded gas
> that was sitting in the car for nearly a year. Does that matter?

Make, model, engine, transmission, year, how many miles on it, how many of
those on current engine, modifications if any, emissions spec (Federal,
California, Canada, other jurisdiction), where you're trying to pass the
test?

DS

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CAR DUDE - 18 May 2004 06:31 GMT

>> Yo dudes! I'm trying to pass the smog check. Man I failed the last
>> time. I got low readings for HC and CO but high readings for NO
[quoted text clipped - 9 lines]
>
> DS

1992 Mazda Protege 1.8L Automatic, 160,000 miles. K&N air filter. Trying
to pass California emissions spec.

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Nate Nagel - 18 May 2004 12:15 GMT

> Yo dudes! I'm trying to pass the smog check. Man I failed the last time. I
> got low readings for HC and CO but high readings for NO levels. What could
> it be? Will changing spark plugs help? What would be the best types of
> spark plugs? What about gas? I was using regular unleaded gas that was
> sitting in the car for nearly a year. Does that matter?

use the factory recommended plugs and I prefer Chevron gas although
any good name brand ought to be OK. I would run the old gas out (or
siphon it if possible) and start with a fresh tank.

good luck

nate

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Tim Brown - 18 May 2004 14:43 GMT

BAd plugs would make your HC high. You need to get your EGR system
checked out, Dude.

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Paul Hovnanian P.E. - 21 May 2004 02:08 GMT

> > Yo dudes! I'm trying to pass the smog check. Man I failed the last time. I
> > got low readings for HC and CO but high readings for NO levels. What could
[quoted text clipped - 4 lines]
> BAd plugs would make your HC high. You need to get your EGR system
> checked out, Dude.

I concur. EGR valves have a habit of carboning up and sticking shut. You
can usually take them out, spray carb cleaner in them and work the valve
back and forth to break it loose. Make sure the vacuum hoses to it are
OK as well.

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Paul Hovnanian mailto:Paul@Hovnanian.com
note to spammers: a Washington State resident
------------------------------------------------------------------
A limerick packs laughs anatomical
Into space that is quite economical.
But the good ones I've seen
So seldom are clean,
And the clean ones so seldom are comical.

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