please help! i love my '07 yukon. a couple of months ago i noticed a miss/hesitation in the engine. i took it to my dealer, they told me i had contaminated fuel. doesnt look right or smell right. i cant hardly believe this, its brand new. i get gas at the same station for all my cars/trucks. none of them have any problem. i go for second opinion. this dealer says no trouble found. gives me a tsb that applies to the 6.0, mine has 5.3 that says this is normal due to stiffer engine mounts etc. i feel as though they didnt want to fool with it either. my buddys brother works at yet another gmc dealer, him and his buddies in the serv. dept. laughed because my dealer wanted to charge me to fix @ $70/hr for 4-5 hrs. to drop tank clean tank pull fuel lines clean everything out. now mind you they dont know exactly what is in tank because they have not looked. they are just guessing until they pull it apart. 30rd dealer didnt fix it either by the way. my gripe is i have a brand new truck that runs like crap and i cant get it fixed. i just dont buy the bad gas thing. i've run several tanks of premium gas and even tried fuel system additives. nothing helps. i'm to my witts end.