I started getting low oil pressure alarms. I would pull over then restart and I would go away. The stabilatrack alarms coming on. Looked at the code reader and saw a P0301 (misfire on cylinder 1). So I made it home and the next day I couldn't make it 2 miles without the oil pressure dipping below alarm set point. I switched the coil packs on cylinder 1 and 2 with no change. I changed all of my spark plugs to find cylinder 1 plug was burnt and gunked up. My mechanic tells me I need a new engine and the same problem was the cause of my high oil consumption. I'm still in shock. I read this post below from this site.

"All of the 2007 and 2008 5.3 motors have an issue with the automatic valve switching or (AFM) which causes these problems being lifter failure, low oil pressure and excessive burning oil. Eventually what happens is you end up replacing the engine like I am doing right now. Very disappointed as I did not know this before I bought, but machining and lifter replacement costs about $2500 where I am getting a new engine for $4400. Disappointed as I needed to get more out of this than I am getting."

I am disappointed because I though Chevy engineered their product to a quality level. The valve switching I always suspected as a terrible idea way to save on gas mileage but had no idea it would have this effect. Sigh..