Preheat oven to 400°F. In a large bowl, whisk together oil, vinegar, garlic, oregano, and red pepper. Add both bags of fajita mix to the bowl and toss to coat in oil mixture. Pour into baking dish. Scatter sausage pieces on top of vegetables.
Bake until vegetables are tender and sausage is cooked through, 40 to 45 minutes.
Top with basil and serve hot.
