I own a 2014 Sierra 1500 Denali with 157,000 miles. On Monday all of a sudden I started getting a light throttle skip or shutter. It doesn't happen on hard acceleration or steady throttle. I hooked a friends scanner to it and it is number 5 cylinder, a few misfires but not a ton. About a year ago I put new GM wires and AC plugs in it. I tried a new plug, coil and wire on number 5 cylinder but it didn't help. Any info would be appreciated. Thanks.