Smoking has many negative aspects in regards to abdominoplasty. In addition to the wound effects, a chronic smokers cough could cause dehiscence of the fascial plication as well.
As an adult, you are making a mature decision to undergo a major surgery. This surgery is very expensive from both a monetary and recovery standpoint. I assume that you want to get the best result ie. your money's worth, thus you should stop smoking at least six weeks prior to surgery and stay that way.