EGR Vacuum Solenoid Valve
WARNING: This page is about a different car, the 1995 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.
Remove EGR vacuum solenoid. Try to blow air through valve. Air should not flow. Apply 12 volts and a ground to solenoid valve terminals. See Figure . Blow air through valve. Air should flow with voltage applied. If valve does not operate as described, replace valve.