emissions trouble

I have a 94 sc2 and it has failed the massachusettes emmission test. I've
replace with new the ox sencor and the catalitic converter, it still
failed, any suggestions??

 

Failing how?? What are readings?

 

it is reading a high hydrocarbons i don't have thenumbers here but will get
them when i get back home.

 

Hydrocarbons in the exhaust means unburned gasoline. That, in turn, usually
means an ignition problem of some sort. Start with the simplest thing: have
you replaced the spark plugs, or at least checked them?

 

You really need to take it to a mechanic that has an exhaust gas
analyzer and the proper diagnostic equipment in order to troubleshoot
this. You'll spend a fortune replacing parts that don't need replacing,
for something that will most likely be something minor like a
disconnected hose or wire.

Not sure if MA has a "gross polluter" designation, but be careful. In
California, if you try to "fix" your emissions problems and make it
worse you can end up as a gross polluter and then you're really in for a
lot of hassle. What would cost you a couple of hundred dollars in
repairs, can end up costing upwards of a thousand dollars.

 

It can also be from low compression and/or oil consumption too. I
would suggest getting several bottle of dry gas or gas antifreeze and
adding it to tank (oxygenates fuel) and then run engine hard for a bit
and "clean" it out a bit and then take it for a emissions check.

 

Sounds like he already took it to a mechanic. Now he needs to take it to
a technician.

 

Move out of the People's Republic of Taxachusetts, to some place where
they still let you drive whatever car you want.

 

Yes, I had the same result when the coolant temperature sensor went
bad.
Replacing it turned my "Fail" into a "Pass".
(I've been through this with both my 94 and 95 SC2 and I've seen this
solve two similar problems on this board.)
It also made the engine idle at a more reasonable RPM.
The sensor resistance was ridiculously high - something like 5 Megohms.
It should have been about 50K ohms at freezing, 100 ohms at 100 degrees
(something like that, anyway)
It caused the engine to think it was running much cooler than it
actually was - apparently running rich to "catch up".
(Although I am aware that a LEAN mixture raises exhaust gas
temperature)

You are definately running too "rich" it the test shows excess
hydrocarbon emmissions.

If this isnt the problem, you've got an injector problem - but I'd bet
the sensor is your culprit. They should be available for less than
$10. You'll loose coolant in the procedure, so drain it down first.
-WaV

 

Not so fast there... all it takes is one spark plug firing only intermittently
to put a pretty fair amount of unburned gasoline (hydrocarbons) in the
exhaust. There are a number of other things that will cause that symptom, too,
and to say that if it's not 'A' then it must be 'B' is simply incorrect.

 

While true - I'd be complaining loudly if I had a miss-fire on a little
4 cylinder 1.9 liter engine!
(I own and maintain two SC2 Saturns. Miss-firing is very hard to not
notice.)
The culpability of the coolant temperature sensor in this vehicle is
legendary.
(Been there. Done that. Not making ANY of this up!)

'If not A and B (replacement of O2 sensor and Catalytic converter),
then probably C and if not - possibly D"
My assumption is based on the original poster's information.
When *I* replaced *my* coolant temperature sensor *I* was 100% correct.
I've gone through the same thing twice with the same model vehicle.
Rebuttal?
-WaV

 

Didn't say you were. I'm just taking issue with your statement that if it's
not the CTS, then it "must" be an injector problem.

That simply is not true -- there are other problems that can cause the same
symptom. I cited a bad spark plug as a simple example; that was not meant to
be a complete list of possibilities.