Diagnostic Aids
WARNING: This page is about a different car, the 1997 GMC Savana, 1997 Chevrolet Chevy Van, and 1997 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
Check MAP sensor vacuum source for leaks, restrictions or faulty connections. Ensure vacuum source only supplies MAP sensor and not other systems such as cruise control, auxiliary vacuum gauges, etc.