trouble started as a P0401 EGR Low Flow on 2001 Ford Escape

I changed all the vacuum lines, changed the ERG, and solenoid pump. The truck stumbles once i put the vacuum line on the ERG valve(runs smooth with out the vacum line on the EGR vavle). Can anyone suggest a system to look at?

Asked by for the 2001 Ford Escape
If you're getting constant vacuum to egr at idle , maybe wrong vacuum line or control signal problem.
1 more answer , 2 more comments
Would help to know what engine you have.
sorry its a 3.0 V6 2WD
Now, try switching vacuum hoses at EGR control solenoid. The black thing with two hoses and wires going to it.
Like next answer suggest wrong hoes to EGR.