Do you have lack of power ? On park, can you rev up the rpm beyond 5500 rpm without flooring the pedal, smoothly without hesitations ?

If this is at the intake manifold, yes the vaccum at idle is very low, should be between 16 and 22 inch Hg.

Two possibilities:
1. EGR valve is malfunctioning, it should be closed at idle but is instead open. The vaccum level at the EGR valve connection should be lower than 2 inch Hg at idle, and about 4-6 inch Hg when the engine is at 2000 rpm.
2. You have a clog in the exhaust system, most likely the catalytic converter. Either disconnect the cat converter at the coupling with the exhaust manifold OR disconnect the manifold from the engine to test.

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Saumil S. Patel