check engine lite is on code reads egr valve excesive flow and not enough flow also misfire on cylinders 1 2 3 & 4 i changed the egr valve the vsv and the modulator that did not work so i tried the timing belt cause it was slapping the cover and that did not work either any ideas?

that's heck of a conflicting messages ha?
Why don't you post miles on the car, actual codes you are getting, how long you had it and any pertinent information about the vehicle like accidents etc.