EGRVacuum Regulator Solenoid
 

I have a 2002 4L and it's idling ruff but seems to run ok under power, somebody told me today that it's the EGR Vac. Reg. He has one that did the same thing and that was it . I've replace the IAC, Plugs, Wires, Fuel filter, Cleaned MAF,Renewed the EGR Valve (Plugged) ... and still not right at idle.

So what does a bad EGV Vac Reg act like ..... Thanks

bought a new EVR today and that solved my problem