Set your Instant Pot to saute.
Add olive oil and pork roast. Seer ever so slightly on each side of the pork roast.
Add tomatoes and taco seasoning.
Set your Instant Pot to high pressure or onto the meat setting.
Cook for 90 minutes. Quick-release pressure.
Open lid. Use a fork to pull apart the meat. The meat should pull right apart and should be really tender.