Newbie here....

Hey guys (and gals), I just bought a C6 S6 two weeks ago and I’m excited and hesitant at the same time.
Im in the NYC area. I’m happy I found this forum, I’ve already learnt a lot and i can’t wait to learn more and try new things with the car.
The car is throughing a few codes: P1075, P0171, P1077 a weird radiator fan knocking sound not sure exactly where the sounds is coming from. I’m hoping this is common and a easy fix, we will see.

So far the car seems bone stock so I did the APR tune and I’m soooo happy I did it. During the tune the tech found a small oil leak which explain the hint of oil scent in the cabin and he also found a hose disconnected. To fix the leak the dealer quoted me ~$1700. $130 parts and the rest is labor. Pre tune the car felt torquey having delays and Boom!!! Whiplash. Now it seems mature steady and smooth acceleration straight through and it pulls harder as it goes through the gears.

Anyways I appreciate the knowledge here keep it coming eventually I’d like to do a catback exhaust, the intake spacer, I wish I could afford headers but then again I’m not sure if I wanna turn that many heads as I’m approaching because I’m sure they’re loud.
I’m hoping the MMI interface can be modded to play videos etc… And I’d like to replace the start stop button, hopefully there is a diy on that.

Peace!!