I saw that you are a tuner, I didn't know this. How much for a tune on my RS6. Do you have different tune's, or just one. I had O.CT tune and frankly it didn't seem much better than stock (other than top end speed limit removal), just worse fuel mileage, so I sold the ECU. How is fuel mileage compared to stock (if cruising)? How was the file developed, are you a dyno tuner? Do you have a money back warranty if I don't like the tune? I plan on gutting my pre-cats so the necessity of ignoring the rear o2 sensors is important to me. Thanks, Jason