In a small bowl, add the marinade ingredients, whisk together, and set aside.
Turn Instant Pot on saute setting, and allow to heat up 3-5 minutes so it's very hot when you add the pork.
Add the avocado oil, and then a couple chunks of the pork. Don't overcrowd the pot, or it will steam instead of brown. Flip the pork over to brown the otherwise, then remove it from the pot. Repeat the process with the rest of the pork. The browned pieces add a lot of flavor to the finished dish.
Turn the Instant Pot off, and then return the pork to the pot. Pour the marinade over the pork.
Set Instant Pot to Manual for 40 minutes.
Allow steam to escape, then remove the pork from the Instant Pot.
Preheat oven to Broil.
Use 2 forks to shred the pork, then place on a baking tray. Add 1/2 of the juice left in the pot to the pork.
Broil pork for about 5 minutes, until the top is crispy. Flip the pork over, return it to the oven, and broil for another 3-5 minutes to crisp up the other side.
Add the remaining juice from the Instant Pot to the carnitas to serve.
Garnish with onions, cilantro, and lime wedges, if desired.