Place the bacon in a large sauté pan. Turn the heat to medium and cook, stirring occasionally, until the bacon is crispy and the fat has rendered. Using a slotted spoon and leaving the bacon fat behind in the pan, transfer the bacon to a paper-towel lined bowl or plate.
Add the onion and green bell pepper to the pan with the bacon fat. Cook, stirring occasionally, until the onion and pepper are tender, 5 to 10 minutes. Remove the pan from the heat.
Preheat the Traeger with the lid closed to 350°F; this will take about 15 minutes.
In a 9 x 13-inch casserole dish, combine the pork and beans, cooked bacon, sautéed onion and pepper, ketchup, dry mustard, black pepper, garlic powder, and onion powder, and stir well to combine.
Place the casserole dish on the grill grate. Close the lid and cook, stirring occasionally, until the sauce has thickened and darkened in color a little, about 1 hour.
Remove the beans from the grill and let cool for 15 to 20 minutes before serving. Enjoy!
