READ THIS!
The problem with your Journey related to the growling noise is the exhaust system. I had the exact same problem. After three attempts to fix the problem, a new exhaust system remedied the situation. I know what you are thinking... What an idiot to suggest such a thing..., but it is true. When you turn the car to the left or accelerate from a stop, somethin is causing the exhaust system parts to resonate and make this sound.
Read this thread.
http://www.dodgejourneyforum.com/index.php?showtopic=201