P0401 issue :(, Somebody has fixed this problem?? Options

[rapidfire]

I saw a lot of posts about the p0401 code, but i can´t find somebody wich fix this code. i already did all this changes to my car.

i changed the next list:
spark plugs wires
spark plugs
distributor cap and rotor
head gasket
fuel pump
fuel filter.
MAP sensor

cleaned:
EGR valve
IAC valve
checked all egr vacumm lines

and i have same problem, same p0401 code, my car its on very slow rpms it shakes on any speed (10, 30, 60 MPH) and i have no idea what else to check to fix this problem ... did someone else having this problem and got fixed??

thank you!!