Italian Sausage, Peppers, and Onions

Ingredients:
2 Tbsp oil
2 lbs sweet Italian Sausage links
2 bell peppers, sliced
2 onions, sliced
3 cloves garlic, minced
15 oz can tomato sauce
14.5 oz can diced tomatoes with juice
1/2 tsp salt
1 tsp Italian seasoning
1 tsp onion powder
1 Tbsp brown sugar
Hoagie buns
Provolone cheese slices
Parmesan cheese