Went to have a smog test done today and the smog place told me that that their smog machine cannot communicate with my 2004 Nissan Xterra XE 2.4L 4 cyl.....? Now the really odd thing is that the OBD2 scanners are able to analyze see and and diagnose the OBD2 system......? There is no codes showing and the system is normal....!! This really bizarre and aggravating grrr....!!!