Your LS has the variable intake system. On my 04 V6 the same codes popped up. Your intake camshafts are not in time with what the computer is telling them to do.
This can happen from bad oil control solenoids, low oil, dirty oil, slipped or jumped timing chains, or bad camshaft phasers. Mine is a bad cam phaser and I could tell when I put new timing chains on that the cams were not aligned properly, I just don't care enough to fix it cause it doesn't affect driving all that much. . . just some lost power at low rpm.