[CREWZIN]

Found this on a search.....

I have a 2003 GT PT. I went to start the car this evening and the check engine light came on. The fault code is P0129, someone on a forum said this is due to barometric pressure? What's happening, is this issue something I need to address immediately? - Joe, from New Jersey.

P0129 - Barometric Pressure Out-of-Range low

Description - MAP sensor input voltage out of an acceptable range detected during reading of barometric pressure.

There are 11 possible causes listed in the diagnostic manual. It covers 3 pages of tests to determine the cause. I've replaced several MAP sensors. It's most likely a defect in the sensor. It's something that should be fixed ASAP.