1. Soak wooden skewers in water 30 minutes to prevent burning.
2. Thread sausage, peppers, and onion quarters evenly onto skewers.
3. Grill, covered with grill lid, over medium heat (300° to 350°) 4 to 6 minutes or until sausage is lightly browned. Turn and grill 3 more minutes; brush with barbecue sauce, and grill 2 more minutes. Serve with additional barbecue sauce, if desired.