Question re failing smog check

Hi. My 97 Accent GT is running just fine, and only has 55k miles on it,
but I took it to get it smog checked in CA the other day and the guy
said it was failing so he shut it down before it reported the failure
to the state.

He said that because he shut it down he has no idea why it is failing.
Suggested MAYBE if I get the oil changed it might help.

My question to you experts is:
What should I do or what can I do to help it pass when I take it in
next week?

Someone else told me that getting an oil change andt tune up will not
help. I already ran a dose of engine cleaner in it, and that apparently
didn't help.

I was very surprised when it did not pass.

How should I proceed? What I am hoping to avoid is a situation where I
take it to a mechanic after it fails and they run up a $300-X000 bill
getting it to pass the test. It really should not be in bad shape with
the number of miles I have on it, and with it running good, not burning
oil or anything...

Thanks for any suggestions.

 

You didn't give us much information on the maintenance history of the
car but if you haven't done so already, you need to change the timing
belt. While your at it, change the air filter, spark plugs & wires -
IOW a tuneup.

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True, but that won't have any effect on emmisions.

Depending on the nature of the failure, that and an oil change may be
enough to get it to pass. Try to find out what pollutants were out of
spec. If it's CO, put a quart of denatured alcohol in the tank before
getting it tested again.

At the age of your car, it's possible that the catalytic converter(s)
is(are) worn out or clogged. If that's the case, replacement is the only
option. If the car is otherwise in good shape and you think it will last
a few more years, it may be worth the cost to do the repairs. If not, do
what I did; sell it cheap to a mechanic who can fix it himself, then buy
another car.

 

There's no real easy answer. Knowing the exhaust data will help a good
technician know where to look. It's possible that changing the oil will
help by removing HC from the PCV system.

Is your check engine lamp on? If so, diagnose that first. If not,
here's
things to make sure of:

1. Your car is running properly. If it isn't performing properly, it's
likely putting out excessive emissions, too. If it doesn't feel like
it's
running properly, start there.

2. Vehicle is properly preconditioned (properly warmed up). This cannot
be stressed enough. Sometimes even waiting in line idling will be enough
to make a vehicle fail. If I have to wait, I usually keep my engine
revved around 2k rpm or so, with a few breaks.

3. The thermostat opens at the proper temperature. If your thermostat
opens too soon, the vehicle will likely never reach proper temperature.
If your engine gets too hot, it will result in excessive NOx.

4. You have the correct PCV valve in the car and it's working properly.
A PCV with too large a port or that is stuck open will cause excess HC.

5. There are no exhaust leaks. This can cause you to fail because
neither the oxygen sensor nor the machine can read your exhaust properly.

There are many other things that can cause a problem, but they become
increasingly difficult to check. If all the above checks out, it's
probably time for professional help.

 

Weird, I replied to this yesterday but it has not shown up so Im
replying again.
There seems to be controversy over whether or not oil changes and
tuneups help.
My guess is that maybe it helps a little, sometimes, and other times
not at all? Would that be accurate?

Just FYI my car seems to be in very good running condition, does not
burn oil, I've kept the oil changed at least every 8k miles, many times
only 3-5k, and I get it tuned up whenever it starts running rough at
all, but it hasn't had an oil change or tune up for m maybe 8k miles
this time.

If I have to change the cat converter, how much should I expect to pay
for that, and does it need to be done at a Hyundai expert such as the
dealer or can any good mechanic do it?

Is it true I should run the car for 20 min or so on the highway (higher
speeds) to warm up the converter right before testing?

 

Or, he could move to Florida. We eliminated auto emission tests (along
with mothercycle helmet laws) when we elected a Republican govenor.

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Your assessment of the oil changes and tune-up is correct. Certainly, if
you haven't changed your oil in 8k miles, you should do so. You've
probably got a significant amount of unburned fuel in there right now.
When your PCV system sucks the vapors out of your crankcase, this will
cause a hydrocarbon increase. You really shouldn't let your oil changes
go that long, anyway.

If your car is running properly, the chances of a tune-up changing
anything are minimal.

In regard to the catalytic converter, it's covered by warranty for 8
years/80k miles. Depending on the mileage/exact age of your vehicle, you
may be able to have it replaced on Hyundai's dime if it's bad. The
chances of needing one and the check engine lamp not being on are minimal,
however. I fully recommend a factory converter. You'll find it's of much
higher quality and functionality than the aftermarkets. This will also
boost the cost dramatically, however. You should call shops and dealers
in your area to get an idea of pricing. It will vary greatly by place of
repair and geographic location.

You should absolutely run the vehicle 20 min or so right before testing.
This is very important. In fact, the harder you run the vehicle, the
better. It helps get everything warmed up properly.

 

Thanks a lot for your help! Hope this thing passes or I'll be back
here with the stats on that...

 

In New Hampshire, we eliminated testing by cleaning up the air to the
point that it wasn't necessary. That seems like a better solution to me.