EGR Valve

With ignition switch turned OFF, activate EGR valve with approximately 9 inches of vacuum, then disconnect vacuum line. If the EGR valve can be heard closing, test vacuum amplifier. If not, bench test the EGR valve as follows.
a. Apply approx. 520 mbar (16 in. Hg) of vacuum with a vacuum pump to the EGR valve.
b. The EGR valve should open fully (approx. 5mm).
c. Pull the vacuum line off of the valve. It should audibly snap closed.
d. If the valve fails any of these tests, replace it.