Today was the secomd time in 5000 miles i have gome in to get a recall done on my 2014 Sierra 6.2 and the service writer tells me each time i really need to have the $145 fuel injection service done. my truck has just over 20,000 on it and runs great. Has any one done this service before or know if its completely necessary? i run fuel system cleaner through it every few months and mainly use supreme when I fuel up.