EGR Backpressure Transducer: Testing and Inspection

1. Remove vacuum hoses "P," "Q" and "R" from modulator.

EGR Vacuum Modulator Check:

2. Plug tubes "P" and "R" with your finger.

3. Blow air into tube "Q." Air should flow to the air filter side freely.

4. Start engine and maintain engine speed at 2,500 rpm. Repeat Steps 1 through 3. There should be a strong resistance to air flow now.

5. Reconnect vacuum hoses to their proper locations.

^ If EGR vacuum modulator fails this test, replace modulator.