Ok, I had my z at my mechanics. my car is runing a little rich. . . he thinks it might be the Afm . I believe the one that is on there is new he said there isnt to good of a way to test it but thinks its the reason some black smoke comes out . . I duno I think it is just the cold start until it kicks off. . . what do you guys think ? I just replaced the thermostat. cause it was sticking . . . I duno !!