I have a 2002 LB7 with 56K miles on it and it is now over 7 years old (Warrenty) it has just started to puff white smoke when left idling for an extended period of time. it would appear that one or more of the injectors are leaking. If GM won't cover do to warrenty experation I will probably replace the injectors myself. What I would like to know are the new injectors from GM redesigned to correct the problem? if not does someone welse sell aftermarket injectors that have been improved to correct this problem? truck gets used primarily to tow 36 foot fifth wheel does not get used around town alot. any ideas would be appreciated. Mark.