I just purchased a 04.5 LLY and when test driving could tell it was tuned. I asked the owner and he "thought" it had a PPE tune on it. Yesterday I purchased an Edge Evolution CTS2 for it. My questions are: Can I hook my Edge up and use it as a monitor without causing issues to the ECM? Do I need to get my trucks ECM flashed to stock before doing any type of tuning with the Edge or will it overwrite what it needs too without causing any harm to the engine or transmission?