98 Accord: Dead Catalytic Converter

Driving from California to Kentucky my check engine light came on. I
thought nothing of it. When I pulled in to KY, I had the dealership
check it out. Turns out, my catalytic converter is dead. Since the car
has only 87k miles on it, the dealer will probably pick up the tab.

The dealer said a potential cause of the failure was the ethanol in
the gas in California. Is this even remotely possible? From what I
saw, there were plenty of Accords in Cali. Any Cali drivers care to
chime in?

cheers,
--Seth
98 Accord Coupe

 

Plenty of Accords in CA and grueling on-dyno emissions tests every two
years in many parts of the state. Not familiar with any epidemic of
converter failures. How long was the car in California? My Civic has
lived exclusively on CA gas for all of its 10 years and is still on the
original catalytic converter. Then again, I don't think we had ethanol
in the gas before MTBE was banned in '99.

If you have too rich of a mixture (e.g. due to a faulty O2 sensor) the
cat could overheat and fail prematurely.

 

I once had an experience here in Canada with my '98 Civic.
Filled up with some bad gas. One tank was all it took, I
could feel the car buckin the whole way home. A week later
my check engine light came on, and they said it was an O2
sensor. So we reset the computer, and the light came on
again a few days later, this time it was the converter.
Upon inspection, they decided to replace it, and it was
warranty. In Canada the warranty for emissions systems is
8 yr/130000km.

This all occured over 5 yrs ago. I just recently had the
exhaust manifold replaced on a recall for cracking, and
boy did they ever have a bugger of a time getting the top
O2 sensor out. The dealer who originally put my old
sensors back in, cross threaded the top one and basically
created a big mess. So anyways, make sure whoever you get
to do your converter has the proper tools and patience to
extract your O2 sensors properly. I am pretty sure that
the sensor was not working properly now that I know what
was goin on. And that part is not covered on the emissions
warranty, and they go for a cool $150 to 200, and can have
a HUGE effect on fuel mileage.

t

 

It had maybe 4 or 5 fillups in CA. Perhaps it was just a coincidence.

cheers,
--Seth

 

I don't live in Cali. but there are several places in the U.S. where there
is oxygenated gas - not sure if we in the N.E. have switched from MTBE yet.
Gasohol with 10% ethanol is approved by Honda and in itself could not
damage a catalytic converter, IMO. There have been problems with gasohol:
even in storage tanks it pulls humidity out of the air - this is the reason
the refiners add it in at the bulk plant load point along with the additive
package.

First, ethanol has a high octane number, of approximately 111 for blending
purposes, so it contributes greatly to the octane number of the final
gasohol blend. If any water from humidity, or other source, gets above
~0.6% (depending on temperature and petroleum components) of the gasohol
blend, the water separates out and takes most of the alcohol with it...
leaving you with a much depleted octane number of the remaining petroleum
portion of the gasohol. We're talking about 3-4points of octane loss,
which could lead to serious combustion problems.

Note also that the tendency for water to separate increases as temperature
goes down - it's more like 0.1% at 0°F IIRC so, e.g. if you did the trip
over the mountains on Cali gasohol obtained at sea-level, the water could
have separated as you drive. Did you have any drivability problems during
the journey? Your car would, of course, try to compensate for any possible
knock but 4 points is a lot to lose for octane

There is lots of controvery on gasohol at present. E.g. it is known that
many (especially older) gas station tanks have water in them at the bottom
and of course this can pull ethanol out of the delivered gasohol.
Depending on how busy the gas station is, how often it gets deliveries,
setttling time allowed and the level of the tank when you buy, IMO there is
a serious increase in the risk of getting "bad gas" recently.

To sum up, the gasohol in itself is not the problem directly, the delivery
system might have been but you can help yourself by being careful about
your choice of gas station: stay away from stations which are down in a
valley where the water table could be near the surface, stay away from
off-brands unless you know the place is supplied from a reputable refiner,
stay away from old places which could have old tanks with accumulated water
in them and hope that you buy at the optimal time following a delivery.
It's also not a bad idea to shove a bottle of (anhydrous) isopropanol based
gas "drier" in your gas tank from time to time... even if not Winter.

I'll add my own semi-political(?) point here: the whole oxygenated gasoline
thing is a fraud perpetrated by bureaucrats and their "scientist"
cronies... with very little in the way of real scientific fact to back it
up, in the way of measured reduction in airborne pollutants. The fact that
it was "suddenly" discovered that MTBE was a serious hazard, from spills
into the aquifers, speaks volumes on the competence of those involved in
this scam. The fact that it takes ~70% more energy to produce a gallon of
biomass-based anhydrous ethanol than you get back from it when burned is
simply a reflection of the D.C. pork barrel (the name Daschle comes to
mind) at work. Hell there's a reason that they have ethanol plants in
petrochemical facilities - it's umm, cheaper to produce the stuff from
petroleum... but still more expensive than to produce gasoline.
"Environmentally friendly" ain't what people think it is!....
<harrrumph>

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??