Does anybody know where exactly the thermostats are at and if so how do you go about replacing them? I am going to try to do that tmrw and I need some help.

 

right on the top front center of the engine, follow the top radiator hose to the cast piece of metal that sits in between the ac compressor and the alternator, its held down by 4 12mm bolts with a bleeder screw on the top of it

 

have an 05 lly duramax was told you can download a program for my laptop to power tune my truck already have adapter from laptop to obdII.

 

there is EFI live and HP tuners, but you have to buy their hardware in order to modify the ECM tuning