I just broke down and purchased an OBDII scaner for my palm. I ended up getting the Auterra http://www.auterraweb.com. I've had a check engine light on for several weeks now and finally got the trouble code. The problem is, I have no idea what it means. This is on a 1998 V70 XC.
The code is P0107 Manifold absolute pressure/barometric pressure circuit low input. If I have to look for a specific sensor, please let me know where to fine it. All along I thought this was going to be the typical O2 sensor.
Thanks in advance for your help.

I am pleased to say that I have solved the problem. The code was linked to the Atmospheric Pressure Sensor. This is located on the front right side of the engine compartment next to the windshield washer refill. After following the steps to verify that the sensor was indeed good as stated in alldatadiy.com, the problem ended up being a poor connection at the terminal to the sensor. Several plug and unplugs made the contact and cleared the fault. Total Cost $0.00. Thanks for your replys.

I do not have the answer you need but I have some info. First take a look at:
http://carprogrammer.com/Z28/PCM/OBD2/GM_SCAN_DATA.htm
http://www.thedieselstop.com/faq/9497faq/maint/pced/99diesel.php3

Here is what the FORD diagnostic for DTC code P0107:

DTC
P0107 - BARO Sensor Low Voltage Detected

Description
*Sensor operating voltage is less than 5.0 volts (VREF), as a result it
failed below the minimum allowable calibrated parameter.

Possible Causes
*Open in the circuit, or short to ground
*VREF circuit open, or short to ground
*Damaged BARO sensor
*Damaged PCM

Diagnostic Aides
*VREF should be greater than 4.0 volts
*PID reading is in frequency


I do not know where this sensor is located (Intake manifold?).

I see in other posts that this may also be called the MAF (Mass Air Flow) sensor which is located on the Air filter box. Some cars have the MAP and some have the MAF. Any thoughts? If this is the case, I've read that it may be as simple as unplugging and plugging the connector (bad connection).
Ray.

That sounds like an O2 sensor fault, but let's see if anyone with more experience confirms.

Regards,

Mike Harris in Sandy Eggo