It all started when I got a code indicating my EGR was the problem. First I cleaned my EGR and since that did not help I replaced it. After getting the same code again I disassembled the Plenum and throttlebody and completely cleaned out the gunk in my EGR port. After reassembling, my idol started surging. It would go up and down up and down as long as my car was in neutral or park. I could drive the car but my idle was too fast in drive. I remove the throttlebody and saw that my idle air control valve was filthy. I cleaned it, reassembled it and still have a surging idle. Any recommendations would be appreciated.