How long should you cook a 9 lb picnic pork shoulder?

Depends on if this is bone in or boneless....

A 16.5 pound boneless pork shoulder smoked or grilled using an indirect method at 225 to 250 degrees should take about 12 hours. Reach an internal temperature of 160 degrees and remove. Cover loosely with foil and let rest for about 30 minutes.... Will continue to cook to about 165 degrees. This allows the internal juices to get back to the middle!!!

Bone in will take a little less time - around 10 hours....

Cook slow and long for best results!!!!!

DeliDave