Exhaust Gas RECIRCULATION: Testing

Looking through opening in EGR valve body, check that valve shaft moves when engine reaches 3000-3500 RPM under no-load condition.
If shaft does not move as specified, remove valve and manually check valve movement. If valve appears okay, check vacuum lines for leaks.

Fig 1: 1974-75 Exhaust Gas Recirculation System (Typical)
Courtesy of SUBARU OF AMERICA, INC.
If valve is sticking or binding, clean or replace as necessary. Check EGR pipe and gas passages from clogging and leaks. See Fig 1. Clean or replace as necessary.

Fig 2: 1976-79 Exhaust Gas Recirculation System (Typical)
Courtesy of SUBARU OF AMERICA, INC.