RepairPal Certified shops can diagnose and repair your 2000 Chevrolet Prizm. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
could be vent soloniod. could be leak too. you need a scan tool, voltmeter and a smoke machine to check it out. or it would be easier to take it to a shop and let them tell you the issue.
Roy