When I was installing a new thermostat, I was able to clear out totally clogged EGR tube (right behind the throttle body). Not surprisingly, P0405 code came right back . I believe that I had TWO problems with my EGR system: a totally clogged tube AND a bad EGR valve. I just purchased one of the ebay special and should be able test my theory in about a week.



BTW, a quick shot of what EGR system does to your intake: