Heat barbecue to high. In a bowl, combine the shrimp and barbecue sauce, turning to coat evenly. Build skewers, alternating shrimp, onion and mango. Finish each skewer with a slice of lime. Lightly brush skewers with canola oil and season with pepper.
Grill for 2 to 3 min. per side, until the shrimp just turns opaque. Remove from the heat. Sprinkle with the green onion and cilantro to serve.