System Check
WARNING: This page is about a different car, the 1997 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.
Check all connectors and vacuum hose routing. Check for cracks, leakage and restrictions, and repair as necessary. Start engine and operate throttle. Diaphragm of EGR control valve should not move while engine is cold. Warm engine to operating temperature. Increase engine speed to about 2000 RPM, EGR control valve diaphragm should move. If no movement is detected, check EGR system components.