Using a sharp knife, cut each sausage lengthwise and remove casing. Discard casing. Place sausage in a bowl. Mash until well blended; roll into 20-25 (2-inch) meatballs.
Preheat outdoor gas grill or grill pan to medium-high heat. Brush grates with 1 Tbsp. oil.
Using your hands, coat skewers with remaining oil. (I used five 12-inch metal skewers). Alternate sausage, bell peppers, onions and pineapple on skewers. Brush with 1/2 cup BBQ sauce.
Place skewers on hot grill and cook, rotating occasionally, until veggies are softened and slightly charred, about 8-10 minutes. Brush with remaining BBQ sauce and cook 1-2 more minutes, careful not to burn.
Remove skewers from grill and brush with more BBQ sauce, if desired.