Hi
I recently purchased an '03 RS6/50k miles with a Unitronic Stage 1 tune. Meticulously serviced by the previous owner with all records. Purchased in Charlotte, NC and driven back to Colorado with no issues. A day after I arrive in CO, the CEL comes on in the morning. I pull the code, generic P0101 "Mass or Volume Air Flow A Circuit Range/Performance." and specific code, DTC17416 P1008 "Mass air flow sensor 1/2 implausible signal." DTC Status sporadic: Open Circuit".
So far my mechanic has performed the following: 55k Service, replaced MAFs and Gaskets. Replaced Air Filters and ensured Air Box was sealed. Smoke test for air leaks. A small hole in the drivers side inter cooler was found. Unitronic Re-flash of the ECU.
So far nothing has fixed the issue. The car seems fine most of the time but their is occasional hesitation when I accelerate. Also note that the CEL goes out on its own and can stay off for a couple of days and other times it comes on and stays on for over a week. I think I've addressed the obvious culprits. Now I'm at a bit of a loss where to look next so any input to this problem is greatly appreciated.