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EGR System

  1. Check and clean vacuum modulator filters with compressed air before proceeding with test.
  2. Disconnect vacuum hose from EGR valve and, using a "T" connector, connect a vacuum gauge. Check that engine starts and runs at idle.
  3. Check BVSV with coolant temperature below 113°F (45°C) on Camry and 86°F (30°C) on Celica. Check that vacuum gauge indicates zero at 2500 RPM on Camry and 3500 RPM on Celica.
    Fig 1: EGR System (Celica)
    G38391Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Check BVSV and EGR vacuum modulator with engine hot. Vacuum gauge should indicate low vacuum at 2500 RPM on Camry and 3500 RPM on Celica.
  5. Disconnect vacuum hose from port "R" of EGR vacuum modulator and connect port directly to intake manifold vacuum.
  6. Vacuum gauge should indicate high vacuum at 2500 RPM on Camry and 3500 RPM on Celica. Disconnect vacuum gauge and reconnect hoses to proper locations.
NOTE: This will cause slight engine misfire due to a large amount of exhaust gas being injected into intake manifold.