Check the engine air filter to make sure it is not clogged.

Check for cracks or holes in the black plastic tube between the air filter
housing and the throttle body.

Check for vacuum leaks.

Temporarily disconnect and plug the vacuum hoses from the EGR valve and see
if the problem clears up.  If it does, remove and clean out the inside of
the EGR valve or replace it.

Check the Mass Air Flow (MAF) sensor that is attached tot he air filter
housing.  There is a tube that protrudes into the air flowing out of the air
filter housing.  You will see a thin wire inside the tube.  If the tube is
dirty or greasy, clean it gently with carburetor cleaner.  Do not break the
wire inside the tube, or you will need a new MAF sensor.

Check the idle air control valve to make sure it is moves freely.  If it
does not, clean it with carburetor cleaner.