Troubleshooting SES light and codes

The Service Engine Soon light came on on my 1996 SL2. Retreived codes
are:

P0341 Camshaft position sensor circuit range/performance
P0133 O2 sensor circuit slow response (Bank 1 sensor 1)
Upstream oxygen sensor response slower than minimum
required switching frequency
P0108 Manifold absolute pressure/barometric pressure circuit high
input
Manifold absolute pressure sensor input above acceptable
maximum voltage

I understand that the P0341 could be a cylinder 1 or 4 plug/wire/coil
issue.

Upon chcking this out, I find the cylinder 1 spark plug well is flooded
with engine oil. So this indicates a leaking valve cover gasket.
Could this preesence of oil contribute to setting the P0341 code?

Is it likely that the manifold pressure really is high (low?). Could
this be related to the leaking valve cover gasket?

Could a plugged PCV valve cause this?

Is there one likely failure that cascades?

I don't want to replace the valve cover gasket only to blow it out
again. I will replace the PCV valve too.

Thanks for any useful suggestions.

Dan

 

The oil covering the #1 spark plug could easily cause the P0341. You should
check/replace the PCV, though I doubt that caused the valve cover gasket to
leak.

As for the other two codes, if you can check the output from the MAP sensor,
it shouldn't be above 4.2 volts with the engine idling. It could be that the
sensor has a damaged vacuum hose that's letting air in, or the sensor could
be bad. The P0133 suggests your oxygen sensor is worn out - if the car has
high miles it could well be, but I'd resolve the first two problems first
and see if the code comes back.

 

Given the age of your car, I'd suggest the following:

1) Replace the valve cover gasket. I think (I'm not sure) that you have the
black plastic composite valve cover. If this is the case, replacing the
gasket it easy. Buy it from the dealer (it's rubber, NOT a bead of silicone
RTV). You'll also need a bit of RTV to deal up the "T" joints - they're the
parts farthest away from the engine near the timing chain. This will clear
up the oil leak.

2) Replace the wires and plugs. The wires are probably shot, and plugs are
cheap. You can get the BKR5E11 plugs from most auto parts places for about
$1.50 each. Gap to 0.040". If your under hood label says 0.060", it's flat
out wrong.

3) I don't know how the Manifold Absolute Pressure (MAP) sensor code would
be related.

4) You probably do need a new O2 sensor on the car too. Replace it.

 

Thanks for the responses. Do I need new plugs? The current ones only have
about 10k on them. The valve cover gasket was replaced by the mechanic at the
same time. I hope I can get more than 10k from the replacement. I think the
wires are original, so replacing them is not unreasonable,even though they
don't looked degraded.

Do dealer supplied parts really have a performance advantage? They seem to
come at a significant price premium.

 

If they've been soaked in oil, and there's been any electrical discharge
along the insulator of the plug (perhaps because of conductive crap in the
oil), then it's a good idea to replace the plugs and the wires. You change
them both at the same time, because if there is any arc-tracking on one
(either the plug or the wire boot) then it can cause more arcing when it's
replaced. The arcing will put an arc-track on both.

I think you might have answered your question before you asked it... Hang
on...

(I am presuming you have the black composite valve cover. I think the 96s
use them. I'm SURE the 97 SL2s do). The dealer gasket comes with four rubber
donuts - one for each spark plug hole. They fit in very well. When I
replaced mine using the dealer parts (after about 70 k miles as I recall)
they worked just fine - no problems, and my two Saturns that I did the work
on have about 30k and 50k miles since I replaced the valve cover gasket.
Now, if your mechanic did the work 10 k miles ago, either he did a very poor
job, or the parts that he used were very poor.

In my younger days, I tried saving money by getting the "best" price on
aftermarket parts. As I've gotten older, I've discovered that the dealer
parts always seem to be the right ones, fit well, and it only takes one
shot* at fixing the problem. On the other hand, I've had to do repeated
repairs on things when I've used the "less expensive" parts. You decide.
But, make sure you find out whether the valve cover gasket failed 10k miles
later because it was an aftermarket part.

* Except for the SL2 Saturns' propensity for eating a new alternator every
30,000 miles or so. As long as you realize that, for the older Saturns,
alternators are a consumable, you'll be fine...

 

Uh-oh ;-)

Is this a general consensus? I just got an older wagon & want to be
prepared. Just replaced the battery...

 

It's a mixed bag. Some guys get 100k out of them. On my 97SL2 I'm on my
3rd alt and 3rd battery in 7 years and 87,000 miles here in Southern
California...

 

OK so I sprang for the Saturn valve cover gasket kit. ($35 with tax). Yeah, it
fits perfectly. But, honestly, probably the only thing wrong with the set I
threw out is a crummy job of torqueing by the mechanic. It looked exactly like
the new one.

Oh, and 89 in-lbs makes a lot more sense when you realize that it's also 10
N-m.

 

OK so I sprang for the Saturn valve cover gasket kit. ($35 with tax).
Yeah, it

Throw out the crummy mechanic too.