July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Possible Causes

Intermittent Condition
5-Volt Supply Circuit Shorted To Ground
5-Volt Supply Circuit Open
MAP Sensor Internal Failure
MAP Sensor Signal Circuit Open
MAP Sensor Signal Circuit Shorted To Ground
MAP Sensor Signal Circuit Shorted To Sensor Ground Circuit
MAP Sensor Vacuum Port
MAP Sensor
PCM 5-Volt Supply Circuit
PCM MAP Sensor Signal