Chrysler Repair: Low Barometric Pressure message, chrysler sebring, month old baby

Question
I have a 2005 chrysler sebring touring sedan. V6 2.7 engine with 102000 miles. Driving it wednesday the engine shifted very hard as I was getting on the highway. I pulled off the road and put the car in park and the oil light came on. Turned the car off and checked oil level - a bit low but not much. Decided to take the car into mechanic's shop but when I went to start the car again the engine light stayed on. Unfortunately I live in a somewhat rural area and I couldn't get a tow truck. I had to drive it into the mechanic's myself. He checked the computer and said it gave him a "barometric pressure low" message. He said he drove it and it was fine. Did a tune up and oil change and since we had a tranny flush within the past 6-9 months the fluid there was clean. Just wondering, he didn't know what the message said and he's "done" with it. Should I bring it to a dealer for further investigation? I have a 5 month old baby and I would hate to get stranded on the road if there's a deep seated problem that needs fixed. Thanks for your advice!

Answer
Hi Kim,
The barometric pressure is measured by a sensor called the Manifold Absolute Pressure Sensor. It senses the local air pressure level before the engine starts and also when the engine is running it senses the dynamic pressure created by the engine cylinders and the throttle valve position. All this is designed to produce the proper fuel/air ratio for optimal engine power output and even to sustain an idle. It could be that the MAP sensor itself is beginning to read inaccurately, or it could be a problem with one of the three wires that connect the sensor to the engine computer. The sensor itself is less than $100 and is simple to replace just being an unplug/plug connection and a couple of screws that hold in in place. It is located on the side of the intake manifold on the side of the engine closest to the front of the car, near the the drive-belt end of the engine. That change out could be done yourself and then hopefully you won't have any other problems and no labor charges. If you get the replacement you will be able to identify easily where it is located.
Roland
PS Sorry for the delay but I just found your question in the 'pool' to which it had been referred by the other expert, Kevin.