well i think i found my problem.. i have a 06 qc 1500 hemi i had noticed a stumble/miss like feel at idle with no codes present or in history. thought it was the plugs, replaced them (champion copper core) and also did the sea foam treatment thinking it would solve the problem, but it didnt. there are no codes present or in history. checked spark on all the coils and its all good. I had a scanner hooked up to it, and did a data stream test and found that there was no activity on cylinders 5 and 6 for ignition dwell, swapped some coils around and it was still the same. but i also have slight coolant loss, there are no leaks present or any signs of leaks, block and everything is clean and no stains of coolant. there is no signs on the t-stat or water pump, the only thing i have noticed is a small damp spot on the block by the right rear corner of the head, but it does not go any further than that spot. i have finally come to the conclusion that the head gaskets might gone and burning the coolant internally, and i very seldom see white smoke coming from the exhaust. did some research and talked to my instructor as i am in my 1st year auto and it is all leading towards a head gasket problem. if it turns out to be the head gasket i would probably just trade it off.