Saute onion and celery and green pepper in oil until vegetables are just soft. Remove from heat. stir into chili sauce, combine 1/2 vegetable sauce mix with ground beef, bread crumbs, egg, worcestershire sauce, salt and pepper. shape into a loaf on a shallow oven proof dish. Bake 350 1 hour. Let stand 5 minutes. Heat remaining sauce. Slice meat loaf, pour remaining sauce over slices.