1996 Saturn SL1 - Service Engine Soon Light

Vehicle: 1996 Saturn SL1 115K miles, 1.9L SOHC Engine
Background: Recently tuned w/new wires and running extremely well for its
age
Symptom: Check Engine Light Illuminated. Goes out when battery disconnected
to reset, but will come back on after driving within 5-10 miles.

I do not have an OBD scanner and know that this is the only way to determine
why the light came on. I would prefer not to pay dealer diagnostic fee if
all that is wrong is a simple Oxygen sensor or something else that would be
simple to replace myself.

I'd appreciate thoughts on possible cause if anyone else has encountered
this same problem. If I don't get any input, I had planned to just replace
the O2 sensor since I know on other vehicles this wears out by 100K and I
know from service records that it has never been replaced. Thanks in
advance for the assistance.

Bob

 

A new O2 sensor at that mileage would not be a terrible idea (assuming it's
fairly cheap, which is likely the case), but there's really no way to know
if that's what's causing the light to come on without a scanner.

I'm told that some places, like AutoZone in the US, will scan codes for you
for free..

 

I really have no idea, but I have that exact same car and had a Check
Engine Soon light go off at around 85000km.

I had a (as Saturn put it) bare spark plug wire, resulting in a misfire.
Replaced it (and another as you can only buy them in twos (again, Saturn
says) and now it's all good.


Chris

 

All,

Thanks for responses. The wires were just changed about a month back when
my son purchased the car used. As I indicated previously, the engine runs
very smoothly and if one of the plugs was misfiring (plugs, wires, coil,
pickup/sensors for ignition) in a 4 cylinder, I think it would be much more
obvious. (This is why I am leaning toward an oxygen sensor or possibly even
a restricted EGR valve.)

I called around and learned that the price for the O2 sensors (I learned
there are two on this model) range from $70-$85 for the exhaust manifold one
and $90-$115 for the one located near the catalytic converter.

I do not own a OBD diagnostic computer, but have considered purchasing if
the cost is approximately the same as the diagnostic charge at the local
Saturn Dealer (about $50 minimum). Can someone provide some advice on these
and/or make a recommendation? How much do these run, where do you recommend
buying from, and with what other vehicles are they compatible?

Also, on the Oxygen sensors, has anyone had bad luck with any specific
brands? The reason I ask is that there is some bad-mouthing of Bosch after
market sensors in another auto.maker newsgroup. Should I stick with the
(presumably Delco) sensor from the dealer which are slightly more expensive?
Which one is more likely to have failed if this is the cause? Any thoughts
or prior experience you can share here?

If I don't get many responses by the end of the day then I will probably
just end up taking it to the dealer to diagnose and then decide on a course
of action once I know what is being indicted by the computer.

Bob

 

--Snip--

Head to an Autozone. They'll scan your car for free. At my local one
they have a unit under the counter for just that purpose. If you don't
have an Autozone, call the various parts stores. There's a chance one
of them might do the same thing. If not, I'd pony up for a diag at the
dealer. Until you know what code is being thrown, you have no idea if
it's something easy or hard, major or minor.


Max

 

....I get a weird miss and hesitation every now and then when one of the coil
towers gets enough corrosion on it on my 97SL2.

 

Did you pay attention that the plugwire routing is correct and that
the gap is at .040" rather than the .060 that some '96s were
stickered at?

Here's a link that refers to these issues.
http://www.magnecor.com/magnecor1/techbulletins/techsat.htm

Ken

 

Thanks. One more thing to look at when I check the plug gap.

 

I just replaced the plug wires. Plugs are gapped at .040. Autozone did a
scan here in WNC and it showed the dreaded PO 341, which is not even listed
in the Haynes manual. So I read up on PO 341, which says the cam sensor is
defective, although there is no such thing as a cam sensor for this engine.
Whew. Would I buy another Saturn?

On top of that the radio still has spark noise. I used the dielectric paste
on the contacts after cleaning them, and yes they had corrosion on 2 of the
towers. The powdery corrosion came off with some rubbing with steel wool.


I will NOT take my 96 SL2 to the local dealer. The devil with them.

 

These vehicles use a compression-sense ignition system which replaces the
function of a cam sensor, it determines which cylinder of each firing pair
is on the compression stroke by measuring the firing voltage difference.
Code P0341 indicates that the cam signal received from the ignition module
had too few or too many pulses per crankshaft revolution. The service info
states that P0341 can be set because of high resistance in the plug wire,
connections, or spark plug.

Basically, P0341 is a symptom of your problem, not the cause.

 

That is indicative of the cylinder 1 and 4 wires not being routed correctly.

 

Saturn recommended plug is NGK.

Ken