My 05 smokes at idle, mainly noticable when lights are behind me at night, but you can see it during the day if you look for it. As soon as it idles up to about 1100 or so RPM at goes away. There is no other unusual smoke at any other RPM. Ive had it in for the reflash (which turned into a huge problem when the battery not charging light came on) but I dont really know what was done, it has a new ECM so i assume its up to date, the dealer says it has everything available from GM on it.

What could cause this? I know now im gonna have hell to try to get the dealer to do anything about it since its straight piped, but it did it before too.

Is it normal? I dont think it is.

Mine did it before I straight piped it too, it seems to smoke less now though. It only smokes a lil and only when it's been idling for some time. For example, today I went to supply house and left truck running(daily routine) well was there for an hour, truck was still runnin, went to post office and noticed it was smokin just faintly white. I just try to orget about it. Just my .02