any real solutions to all the above complaints i have a 2015 sierra denali 6.2 that at a red light shakes bad in seat only as day goes on in morning its fine once up to temperature the problem starts! Anyone have dealer put coil pacs or wires on it, can it be a torque converter? I'm at my whits end with this truck and about to trade for a toyota truck which is a shame love the truck when liberation starts hate the truck. gm corporate has been useless on this issue