EGR Backpressure Transducer: Testing and Inspection

EGR Modulator Inspection - Engine Stopped:

EGR Vacuum Modulator Inspection
(a) Disconnect the vacuum hoses from ports P, 0 and R of the EGR vacuum modulator.
(b) Block ports P and R with your finger.
(c) Blow air into port 0, and check that the air passes through to the air filter side freely.
(d) Start the engine, and maintain speed at 3,500 rpm.
(e) Repeat the above test. Check that there is a strong resistance to air flow.
(f) Reconnect the vacuum hoses to the proper locations.