EGR Backpressure Transducer: Testing and Inspection

- Disconnect the vacuum hoses from ports P, Q and R of the EGR vacuum modulator.
- Block ports P and R with your finger.
- Blow air into port Q, and check that the air passes through to the air filter side freely.





- Start the engine, and maintain speed at 3,000 rpm.
- Repeat the above test. Check that there is a strong resistance to air flow.
- If operation is not as specified, replace the EGR vacuum modulator.
- Reconnect the vacuum hoses to the proper locations.