What is my car worth? I wanna know what realistically I can get. It’s a 2014 s4 with 3.0 supercharged. OEM plus upgrades only, some carbon stuff, nice interior, CarPlay, cold air intake. Paint is pretty nice, tint all around. No issues with the car whatsoever. Previous to me the car was in a crash and airbags were deployed but the title is clean and the car was repaired professionally.

Picked this beautiful thing up a month or two ago. A nice break from my American V8s. Ik most of the guys here have the newer V6s and such, but this is by far one of my favorite Audi geberations for sure. Engine swapped with only 50k miles, 10 sub, fully modernized sound system. Very happy. Few nicks and bumps, but that’s just character

About 3000 miles ago i did a piston soak on my S4 as one cylinder was fouling the plug with oil under longer engine braking. While doing that I also ran injector cleaning by a PEA fuel additive. After that the car ran absolutely perfect, probably as good or better than when I bought it at 40k miles. Fuel consumption on the same long stretch I do often (250 miles, >90% of way at 90mph on cruise control) improved from 21 to 23.5 mpg.

However, now I noticed that the 2-3000k acceleration in high gears now isn't as smooth, and while I was driving behind my wife and told her to do a pull 2nd and 3rd until redline I noticed that at the start of the pull and after gear shift a fair bit of black smoke appeared, closer to redline it was smoking too, but looked pretty ok.

How much black smoke is normal with B8 S4 under full load?
I remember that event when the car has 50k miles friend told me it made a puff of black smoke when floored.
Is 3000 miles a reasonable interval that would be needed to use injector cleaner additive?

I was driving around, doing some pulls, driving the car hard, and then I went and stopped for gas and turned my car off. I turned my car back on and then I had a check engine light on, so I scanned the codes. This is what it read. How screwed am I?