Code 13
WARNING: This page is about a different car, the 1995 Jeep Wrangler and 1995 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
Scan tool displays NO CHANGE IN MAP FROM START TO RUN. Condition is: no difference recognized between engine Manifold Absolute Pressure (MAP) reading and barometric (atmospheric) pressure reading at start-up. MIL will come on.