Calif. Models with M/T
Diaphragm is used to stop operation of EGR system during deceleration whenever intake manifold exceeds 25 in. Hg, by closing vacuum passage from vacuum amplifier and bleeding air into EGR valve to seat valve. See Fig 1 .
NOTE:
Valve is used to stop operation of EGR system if engine vacuum exceeds 25 in. Hg during deceleration.