Saturn Repair: 1991 Saturn High Idle, positive crankcase ventilation, throttle position sensor

Question
I have just purchased a 1991 Saturn two door for my daughter's first car. The car idles at about 2500 rpm when in park. It does'nt idle down at any point until putting it in gear.  I need to take it for emission testing and was told that it won't pass with the high idle in park. I am planning on taking it to a repair shop but would like to have some knowledge so I'm not taken advantage of. Any info would be greatly appreciated.

Thank You,
Paula

Answer
Paula,
 You have found a rare automobile.  Not many '91 Saturns were produced, and many haven't survived thus far.  They are not bad cars they were just re-vamped for the '92 model year.  Also, double check your VIN number/title registration.  If it is a two door, it is probably a '93 model.  I believe that was the first production run of the S-series coupe.  Anyway, back to your question.  A high idle can be caused by a number of problems.  The first thing I would check would be the Positive Crankcase Ventilation hose, or PCV hose.  This is a black hose with a 90-degree elbow on it.  This hose runs from your cam cover (silver cover on top of the engine, about 16 inches wide by about 6 inches deep. Should be the first thing you see when you open your hood.)  BE CAREFUL, but with the engine running, run your hand across that hose and see if you can find a vacuum leak.  (kinda like putting your hand on the end of a vacuum cleaner, it will try and grab your finger.) If you don't find a vacuum leak, I would suspect a faulty Idle Air Control Valve, or Throttle Position Sensor (IAC Valve & TP Sensor, respectively).  You can attempt to reset their values with the following procedure.  
1. Engine off, key off.
2. Disconnect positive and negative cables from battery (red and black)
3. WITHOUT touching the loose cable ends to the battery, touch the metal contacts on the positive and negative calbes to EACHOTHER.  This will remove most all of the electricity from the PCM, and will reset the values that the IAC valve has "learned".  
I would probably venture to say that you have a vacuum leak though. That fits the description of your symptoms, especially if the high idle is noticed right at startup and continues until you put it in drive.  A vacuum hose is an easy fix, and not counting time for diagnosis, you should be able to get in and out of a reputable repair facility for $40-$60. Remember, that is not counting what they charge you to find the problem, but that shouldn't be more than the cost to actually fix the problem.  
Hope this helps!
Chris