EGR Modulator
- Remove EGR modulator. Plug one upper vacuum hose fitting while blowing air into remaining upper vacuum hose fitting. Air should pass through filter.
- Connect vacuum pump to one of the upper vacuum hose fittings. Plug remaining upper vacuum hose fitting (exhaust gas pressure port). Blow air into bottom vacuum hose fitting, while applying vacuum with vacuum pump. Vacuum should be obtained. Replace EGR modulator if defective.