EGR Modulator
- Disassemble modulator and check filter. Clean filter with compressed air (if necessary). Reassemble modulator. Remove modulator and plug No. 1 side nozzle. Blow air into No. 2 side nozzle. Air should pass through filter freely. See Fig 1 .
- Attach vacuum gauge to nozzle No. 1 and plug nozzle No. 2. Blow air into nozzle No. 3, operate vacuum pump gauge and check that vacuum is applied to modulator. Replace modulator as necessary.