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EGR Vacuum Modulator

  1. EGR vacuum modulator may be a 2 port or 3 port depending on application. On 2 port models, disconnect hoses from vacuum modulator. Plug one end of hose connection on EGR vacuum modulator.
  2. Apply air pressure through remaining port. Air should pass freely through air filter side. On 3 port models, disconnect all hoses. Block "P" and "R" ports. Apply air pressure to "Q" port. See Fig 1. Air should pass through the air filter side freely.
    Fig 1: Testing 3 Port Vacuum Modulator
    G67577Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. On all models, operate engine at specified RPM due to model application. See EGR VACUUM MODULATOR SPECIFICATIONS  table. Repeat previous test procedure. Strong resistance of air flow should be felt. Replace EGR vacuum modulator if resistance is not felt.