Csk Or Something Else?

[rob6773]

I have been reading a bit on piston slap and am still not sure if I have something else going on. My truck is an '04 Z-71 w/a 5.3. When I sart it up it sounds a bit like a diesel for a couple of minutes(3-4), but not insanely loud. When the truck has been run then cooled down for 1 to 3 hours and I start it then it really sounds bad (knocking) for 1 1/2-2 minutes. It seems to be getting worse. I put on a corsa dual exhaust that is kinda loud and I still hear the knock from way across a parking lot. (I have a remote start.) Is this CSK or could I have something else going on? My truck seems cursed, it has had every common problem posted on this board and a few problems the silverado is not known for. I bought it w/17K on it and it now has 34K. I do have an extended warranty on the truck. I use Mobil 1 5-30 w/lucas syth. stabilizer and a K&N oil filter.