2002 Audi A6 2.7t Stage 1

I have searched high and low all over the internet to figure this out, so yes I did do my research :P

I was getting stuttering issues and my car would stall out and I would have to pull over, turn it off and back on to get back on the road, especially when I would get over 60mph. I got 4 codes 0171, 0172, 0174, 0175 and 0442.

The first four all relate to both banks being too rich and too lean.
0442 says small leak in the fuel system, I got a new fuel cap but its still up, I don' think this is my issue though.

I tried unplugging the MAF sensor and running the car, it ran great! Just doesn't have a ton of boost when it gets warmed up. I REPLACED the MAF sensor, a Hitachi from ECS Tuning. I plugged it in and still had the same problem.

I checked my boost lines and TBB (throttle body boot) and looked at my DVs (Diverter Valves) and I DO NOT see any noticeable rips.. Also ran a throttle body adjustment with my APR Fully Loaded Chip.

Important Note: I was running the APR performance chip (Fully loaded, 4 programs: Stock, 91 Octane, 93 O, 100 O. I was running 91 Octane pretty hard without any part upgrades (I know stupid, right?) so I am sure this is related. I am currently running stock to be safe.)

I ordered a Samco TBB and Samco upper boost hoses, so maybe this will help, will be here next week. I plan to buy 034 Motorsport bipipe and 710N Diverter Valves (Maybe 008 as I plan to upgrade to K04s one day).

Am I on the right track here? Does anyone know what my issue really is..? Thank you for your help fellas.

 

Wild guess: failing fuel pump maybe?

 

That would make sense. You know whats funny? I ordered one when I got the new MAF sensor and I haven't had a day off to install it. I try it and see what happens. Thank you!

 

You could also replace the fuel filter while you are at it, just to be on the safe side that fuel flow is not restricted.