Heat 1 tablespoon oil in large skillet over medium-high heat. Add sausages; sauté until brown, about 5 minutes. Transfer to paper towels and drain.

Bring large pot of salted water to boil. Add potatoes; cook just until tender, stirring occasionally, about 9 minutes. Drain well. Whisk vinegar, pepper sauce and mustard in large bowl. Transfer warm potatoes to bowl with vinegar mixture and gently toss. Gently mix in sausages, bell pepper, celery, green onions and 1/4 cup oil. Season with salt and pepper. Serve warm or at room temperature.