How accurate is 32 MAP sensor code(95SL2)

I have approx. 138K miles on a 95 SL2. The motor quit twice
now; once while my wife was slowing down to 25mph and with
me while coming to a stop from a slow speed of about 30mph.
So far, the motor hasn't quit after it has warmed up. I used
an Autoxray 2000 to scan for codes. The only code present was 32 MAP
sensor low. I cleared the code and tried to duplicate the problem. The
motor hasn't quit again so far,
however the SES light did come back on after 3 miles of driving. I scanned
again and got the same code. I know that
ATE (automatic testing equipment) isn't always on the mark,
depending on how the microprossor is interfaced with the sensor's and how
the instructions were written to interpret
the values coming back from the sensors. Sometimes bugs can
be masked by others and the code you get is inaccurate.
If any one has any experience in this area, I would greatly
appreciate any info you have. Thank You.
Some basic things I've checked:
The battery is charging a little over 14VDC
I've kept a rusty belt tensioner freed by spraying a lubricant in it.
And I noticed a brittle hose between the vavle cover and air
intake duct.

 

This could be an intermittent connection. basically, it thinks the
sensor's not there. If you unplug the car and start it, you'll get a
code 32.

Ok, it's consistent

I bet that's what's causing your code 32 - that's the hose that runs
from the PCV valve (in the valve cover's rubber plug) to the intake
manifold. A leak or busted hose there could cause high idle, or funky
vacuum things, since it goes into the manifold.

Replace that hose and make sure the PCV valve stays in tight. It's only
a few bucks and PCV is a great thing - makes your engine last longer.
And, might clear up that 32 code.

Here's an interesting clue, though:

I can think of a few things here:

* Coolant temperature sensor.
* Stuck EGR valve or busted solinoid, allowing EGR before the car's
fully warmed up.
* Thermal related issue with MAP sensor.

In that order, too. Coolant temp sensors are a common failure on
Saturns, they generally manifest themselvs as poor starting in the cold,
poor cool engine performance, etc. That this goes away when the
engine's warm sugessts that it might be the CTS. Very easy to fix, and
cheap. A failed CTS may not always give a trouble code, too.

Stuck EGR or busted solinoid is another thing - IIRC, the Saturn keeps
EGR off until the car's warmed up. If the EGR's working while the car's
cool, it could cause stalling maybe.

Thermal issue with the MAP sensor? It's intermittent while cold but not
warm? Hey - bizzare shit happens. I wouldn't bet on it though - I'd
think a bad MAP would cause a LOT of driveability issues, not a check
engine light.

 

Phillip,
Thanks for the tidbits. I was wrong about the MAP sensor; Autoxray said
map sensor low with a fault code of 32. Data
showed about 1.5vdc while the motor was running. I thought
that was low, so bought a map sensor and that wasn't it.
Then I noticed in Chilton that your suppose to have the motor off and the
key on. I then read 4.6 which was exceptable. Autoxray's text on the fault
was miss leading.
I used the 2000 model initially and the 32 code was solid,
I could clear it and after 3 miles of driving it hard fail
again. I then upgraded to the Autoxray 5000 model so I could
read data. At the same time I bought a map sensor. After installing the
map sensor, I tried to clear the code with
the 5000 model and it wouldn't do it. I went to the local
saturn dealer and bought a EGR valve, idler pulley, CTS, and
serpentine belt. I already had a tensioner pulley. You were
right, the EGR valve was the problem. One of the mechs at
the dealership comfirmed the same thing. After repacing the
EGR, I cleaned the trottle body, which was just beginning to
stick a little. My belt was churping and squealing; the idler pulley and
tensioner fixed that. I didn't replace the
CTS yet, mine was not cracked and leaking, however, parts
said they sell 3 or 4 cts's a week. I'm not sure if this
Autoxray 5000 is working right or if the computer was just
acting up. I had to do it the slow way and pull the battery
cable which worked. My wife says it drives great and it hasn't died on me
yet. Hopefully it will stay that way for
awhile. Thank you again for your comments.

 

Score!

Ooo, did you clean it with spray junk or did you remove and really clean
it out? The latter gets stuff the former won't, and is easy too.

Yeah, been there, done that.

Be ready to! They fail in other ways besides leaking, and without
popping on a trouble code. Cold engine acting up is a dead ringer for
it.

 

Mine failed in the opposite! As soon as the computer went into closed loop
operation (warmed up), it would idle rough, hunt and stall. Then it
wouldn't start. When I did get it to start (throttle wide open, long
cranking), it blew black/grey smoke, missed, etc. Too rich.

Code 15 led me straight to the CTs (low temp). Replaced it and all is
well in the world again. 270,000 miles and counting....

 

Seems Autoxray may be at fault my 93 service manual says code 32 is EGR
system fault!