I need some help!!! This is my second go round with problems on my 2005 z71 ls crew cab I5 engine. At approx. 35,000 miles the dealer had to replace all valves, valve springs, a piston and the head. Now at 75,000 miles I have a horribly rough idle. The OBD II reads LOW RPM AT IDLE, and when coasting the engine cuts off. If I sit idling the truck vibrates badly. When the car stalls I have a difficult time getting it to the side of the road to stop and restart. I havent taken it to the dealer yet because if it is not covered under that new 100,000 mile warranty I cant afford to fix it. I am desprate please help me!