94 Accord Wagon Failed Emmissions

94 Accord Wagon Failed Emmissions - Running Hot?

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Mark Lewis - 13 Jul 2005 01:20 GMT

My 1994 Accord Wagon, 172k miles, failed emissions for NOX. I am told that
my combustions chambers is running "hot" but the Catalytic converter may
still be ok. One suggestion is to add some alchol before trying the test
again and also to make sure the engine is a cool as possible. Someone
else<g> has told me to get some magic additive that is sold in auto parts
stores to fix my problem...another genius suggests a run of Gum out.

I am willing to spring for a new catalytic converter if it fails a retest
and if that will certainly fix my problem. Can anyone explain what my
problem is, in layman's terms, and the validity of some of the helpful
suggestions from my buddies?

Thanks,

Mark

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TeGGeR® - 13 Jul 2005 02:30 GMT

> My 1994 Accord Wagon, 172k miles, failed emissions for NOX. I am told
> that my combustions chambers is running "hot" but the Catalytic
> converter may still be ok. One suggestion is to add some alchol before
> trying the test again and also to make sure the engine is a cool as
> possible.

You may fail on high HCs. Don't put crap in your gas to mask an unrelated
problem. Find the real problem first.

Prep the car with long, hard run on the highway immediately beforehand to
make certain the cat is up to temp.

> Someone else<g> has told me to get some magic additive that
> is sold in auto parts stores to fix my problem...another genius
> suggests a run of Gum out.

Chevron Techron injector cleaner isn't a bad idea, but not right now.

> I am willing to spring for a new catalytic converter if it fails a
> retest and if that will certainly fix my problem. Can anyone explain
> what my problem is, in layman's terms, and the validity of some of the
> helpful suggestions from my buddies?

DO NOT replace that cat. It is the LEAST likely culprit.

Your problems range from defective EGR to overly advanced timing to a lean-
biased O2 sensor to gummed-up injectors to daily variance in the emissions
testing equipment (up to 400% variance per day).

http://tinyurl.com/axsuo

http://www.asashop.org/autoinc/oct2004/techtips.cfm

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TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

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Mark Lewis - 13 Jul 2005 11:24 GMT

Thanks. Not very comfortable with dumping stuff in the tank... The dealer
did check the car out after the failure, would their diagnositics
highlighted any of these other items?

Mark

>> My 1994 Accord Wagon, 172k miles, failed emissions for NOX. I am told
>> that my combustions chambers is running "hot" but the Catalytic
[quoted text clipped - 29 lines]
>
> http://www.asashop.org/autoinc/oct2004/techtips.cfm

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TeGGeR® - 13 Jul 2005 12:13 GMT

> Thanks. Not very comfortable with dumping stuff in the tank... The
> dealer did check the car out after the failure, would their
> diagnositics highlighted any of these other items?

Depends how competent they are in diagnosing failures. Dealers are not
usually the best place to bring an older car for diagnosis, since they
specialize in the new stuff.

Also, you have not posted any of your actual numbers (or the limits in your
area), so it's difficult to help you further.

If you book a retest at a different facility, or at the same place a week
later, you may pass without any work done at all to your car. Seriously. If
you fail again, then more attention is needed. Until then I would do
nothing.

Check out my numbers:
http://www.tegger.com/hondafaq/misc/91_integra_emissions.html
See the June 2003 NO numbers? I did absolutely nothing except oil changes
and the usual maintenance between then and 2005, and NO plummetted.

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TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

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Mark Lewis - 14 Jul 2005 00:54 GMT

The numbers are:

HC (PPM)
Limit 136
Emmisions 7
Pass

CO(%)
Limit .73
Emissions .02
Pass

NOx (PPM)
Limit 1591
Emissions 2186
Fail

Does this help at all? I am certainly going to try again at another place
after a long ride there.

Thanks,

Mark

>> Thanks. Not very comfortable with dumping stuff in the tank... The
>> dealer did check the car out after the failure, would their
[quoted text clipped - 18 lines]
> See the June 2003 NO numbers? I did absolutely nothing except oil changes
> and the usual maintenance between then and 2005, and NO plummetted.

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TeGGeR® - 14 Jul 2005 01:41 GMT

> The numbers are:
>
[quoted text clipped - 12 lines]
> Emissions 2186
> Fail

You are running WAY lean according to these numbers.

First step: Take the car in for a retest with NO work done. You have a
better than even chance of passing.

If it fails second time around, check for:
1) A leak in the exhaust before the cat
2) Ignition timing too far advanced
3) EGR valve not opening
4) Lean-biased O2 sensor (replace to check).

Signature

TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

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jim beam - 14 Jul 2005 02:46 GMT

>>>Thanks. Not very comfortable with dumping stuff in the tank... The
>>>dealer did check the car out after the failure, would their
[quoted text clipped - 37 lines]
>
> Does this help at all? I am certainly going to try again at another

place

> after a long ride there.
>
> Thanks,
>
> Mark

i agree with tegger you're /way/ lean. run a couple of tanks of
injector cleaner through - make sure you do some extended /full
throttle/ hills as part of that. if that doesn't work, go for a new
oxygen sensor. don't re-test while you still have injector cleaner in
there.

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jim beam - 13 Jul 2005 03:03 GMT

> My 1994 Accord Wagon, 172k miles, failed emissions for NOX. I am told that
> my combustions chambers is running "hot" but the Catalytic converter may
[quoted text clipped - 11 lines]
>
> Mark

check the ignition timing, and egr.

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