EvergreenZ71
Full Access Member
Ditto on this.definitely check your cabin filter.
then run by dealer & have them check the status of "afterblow" feature in your ECM. have them enable it , if it is not.
I just had my local dealer do this to both my 2009 Tahoe LTZ & my 2010 Sub 2500. Wife’s 2006 Envoy is getting it next.