Combine all the Sauce ingredients in a large bowl and stir well to fully combine.
Add the pork pieces to the Instant Pot and pour the sauce on top of them.
Lock the lid, make sure the valve points to sealed. Select High Pressure and cook for 60 minutes. When the pork is done cooking and you hear the beeping sound, do a 10-20 min natural pressure release. Release manually the remaining pressure and carefully remove the lid.
Gently remove the pork from the pressure cooker, add it to a large, dip dish and shred it using two forks.
Strain the cooking liquid, and reserve about 2 cups.
Select Sauté and add the shredded pork back to the cooking pot, add the remaining 1 cup of barbecue sauce and ½ cup of the cooking liquid. Stir to combine and bring to a simmer, stirring and tossing frequently. If needed add another ½ cup of cooking liquid.
Serve pulled pork immediately on buns, if desired top with coleslaw and more barbecue sauce.
Store in the refrigerator the remaining 1 cup of cooking liquid, you can use it to reheat the pulled pork, in case it needs more liquid.
Store pulled pork in an airtight container in the refrigerator for 3-4 days.