Honda Car Forum

I've had my honda civic's emission system tested three times and it failed
three times. I've changed the spark plugs, oil, wires, distributor cap,
rotor, o2 sensor, and the air filter. Does anyone have any suggestions on
what else needs to be done? The reading for the last test on HC was 224
with the allowed being 147, CO reading was 2.10 with the allowed being
0.82, and the NO reading was 1825, with the allowed being 1072. All of
these readings were done on the 25/25 test. On the 50/15 test, the
reading for HC was 195 with the allowed being 152, CO was 1.48 with
allowed being 0.85, and the NO was 1808 with allowed being 1186. I just
changed the oxygen sensor but I don't want to have it tested if there are
other things that needs replacement as well. Any help is appreciated.

What were the readings for O2? I know there is no pass / fail for O2,
but it is valuable to know for diagnostic purposes.

If there is plenty of O2 in the exhaust, it would seem your catalytic
converter is not doing its job.

snakeman wrote:
>
> I've had my honda civic's emission system tested three times and it failed
> three times. I've changed the spark plugs, oil, wires, distributor cap,
> rotor, o2 sensor, and the air filter. Does anyone have any suggestions on
> what else needs to be done? The reading for the last test on HC was 224
> with the allowed being 147, CO reading was 2.10 with the allowed being
> 0.82, and the NO reading was 1825, with the allowed being 1072. All of
> these readings were done on the 25/25 test. On the 50/15 test, the
> reading for HC was 195 with the allowed being 152, CO was 1.48 with
> allowed being 0.85, and the NO was 1808 with allowed being 1186. I just
> changed the oxygen sensor but I don't want to have it tested if there are
> other things that needs replacement as well. Any help is appreciated.

snakeman wrote:
> I've had my honda civic's emission system tested three times and it failed
> three times. I've changed the spark plugs, oil, wires, distributor cap,
> rotor, o2 sensor, and the air filter. Does anyone have any suggestions on
> what else needs to be done? The reading for the last test on HC was 224
> with the allowed being 147, CO reading was 2.10 with the allowed being
> 0.82, and the NO reading was 1825, with the allowed being 1072. All of
> these readings were done on the 25/25 test. On the 50/15 test, the
> reading for HC was 195 with the allowed being 152, CO was 1.48 with
> allowed being 0.85, and the NO was 1808 with allowed being 1186. I just
> changed the oxygen sensor but I don't want to have it tested if there are
> other things that needs replacement as well. Any help is appreciated.
>
++++++++++++++++

You didn't mention changing your PCV . . . Very easy to do on most
Hondas, and often overlooked when mileage suddenly goes down the toilet,
or oil consumption rises.

Do a google search to learn more.

'Curly'

I think the O2 reading on the 25/25 test was 16.1 and on the 50/15 test it
showed 15.9 with the allowable on both being 6.0.

Thanks, I'll check into that.

Thanks,I'll check into that

snakeman wrote:

> I've had my honda civic's emission system tested three times and it failed
> three times. I've changed the spark plugs, oil, wires, distributor cap,
> rotor, o2 sensor, and the air filter. Does anyone have any suggestions on
> what else needs to be done?

sounds like youve done everything but the catalyst. make sure the timing
is set to spec too, and id check the valve clearance. a compression
check would also be handy, to see how the rings and everything else are.

You need a catalytic converter.




"snakeman" <mrruck@hotmail.com> wrote in message
news:fe001dddb05940659ad199ddac17e09b@localhost.ta lkaboutautos.com...
> I've had my honda civic's emission system tested three times and it failed
> three times. I've changed the spark plugs, oil, wires, distributor cap,
> rotor, o2 sensor, and the air filter. Does anyone have any suggestions on
> what else needs to be done? The reading for the last test on HC was 224
> with the allowed being 147, CO reading was 2.10 with the allowed being
> 0.82, and the NO reading was 1825, with the allowed being 1072. All of
> these readings were done on the 25/25 test. On the 50/15 test, the
> reading for HC was 195 with the allowed being 152, CO was 1.48 with
> allowed being 0.85, and the NO was 1808 with allowed being 1186. I just
> changed the oxygen sensor but I don't want to have it tested if there are
> other things that needs replacement as well. Any help is appreciated.
>
>

16% would be VERY high for O2. are you sure it is O2 and not CO2 that is
16%

snakeman wrote:
>
> I think the O2 reading on the 25/25 test was 16.1 and on the 50/15 test it
> showed 15.9 with the allowable on both being 6.0.

That was my error on the previous post. The CO2 reading is 16.1 on the
25/25 test and 15.9 on the 15.9 test not the O2 reading