1993 Geo Tracker LSi, AutomaticFACTORY OEM SERVICE PROCEDURE

EGR Modulator

  1. Remove EGR modulator. Plug one upper vacuum hose fitting while blowing air into other upper vacuum hose fitting. Air should pass through filter.
  2. Connect vacuum pump to either upper vacuum hose fittings. Plug other upper vacuum hose fitting (exhaust gas pressure port). Blow air into bottom vacuum hose fitting while applying vacuum using vacuum pump. Vacuum should be obtained. Replace modulator if defective.
EGR VACUUM SWITCHING VALVE LOCATION

Application Location
Tracker (1) Forward Of Valve Cover
(1) Connector has Light Green/Red and Light Green/Yellow wires.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.