2012 Fiat Abarth 186000 miles
Current Setup:

RRM piggyback (1st generation) installed and set at 7, been on car for 8yrs (no issues before this).
Stock filter box with a BMC filter recently cleaned less than 500 miles ago.
Alfa 4c coils
NGK DCPR9EIX spark plugs (change less than 500 miles ago)
Turbosmart BOV Kompact EM Dual Port VR15
Turbosmart Wastegate Actuator


Before throwing the listed codes; there had been a check engine light on for P1185 / P0006d after oil change / AOS was cleaned.
Car wont go past 10psi boost; due to limp mode. Slight stumble at low rpm's
So the last couple of months I went through the car to t/s the listed error codes above. Here is a list of what was done.

Serviced AOS / PCV valve again
Throttle body was cleaned / replaced with OEM
Boost Pressure Sensor was replaced with new OEM
MAF sensor was replaced with new OEM
Battery was replaced in July
Cleaned battery ground connection to the frame
Wastegate solenoid was replaced with new OEM
Checked hoses for any holes / splits
Cleaned / checked connections

So today I removed the RRM piggyback; all back to stock connections. Fire up the Fiat; NO check engine light
Oddly the Low fuel message popped up on the dash. Range is showing ----- : Gas tank was at 1/4 tank
Go get gas and take the car out for a drive when the Lighting Bolt and check engine appeared again; i was going 35mph on a flat road with steady throttle (sport mode on).
The outside temp was about 44. Car ran fine for 12 miles; and back to more codes.

Trying to narrow what the cause and how to fix it?

P2175 - Throttle Actuator Control System - Low Air Flow Detected
P1185 - General pressure sensor correlation
P0234 - Turbo Charger Overboost condition


I've read most forum articles and they seem to go in different directions; depending on the car.

Any good mechanics in the RI / MA / CT / NH area that will work on Fiat?

TIA