The control looks a little hot. You might try lowering your P value to 2.5 and raise your I value to .003. Not sure what your using for your damper, but once you flatten out the oscillations, you can start playing with the fan settings. Oscillations usually mean the Gain is too high and the intregal is too low. Also be careful your pit probe is not seeing direct flame from coals. Pit probe needs to monitor the grills air temp, not direct flame temp. Close to coals is good, but no flame. Last, make sure your seal up well and air comes in damper and out the exhaust of grill. I know these grill do not seal like ceramic grills, but a well sealed grill does control better. You might also try some lump charcoal. Royal Oak brand from HD works well and burns long.