Intermittent codes on PD140 BKD, next move?

Aug 27, 2021
West Midlands
Where to start... a few months back I bought a PD140 BKD Leon reference sport that had been sat for months in quite the state, I thought it would be a fun project to learn with as there was a little bit of everything to work on, it's been a fun journey and for the most part its back to a drivable car.

For context as far as I am aware the car has been remapped, how well I do not know, forgive me if this is as hard to follow as it is for me to write.

The first cause for concern I ran in to was the radiator fans running at high RPM whenever the ignition was switched on no matter the outside temperature, that has now appeared to clear itself up with no logical explanation, I ran diagnostics and have a fair few codes that I am dealing with on a very intermittent basis sometimes returning after a short journey, sometimes not returning for 3 or 4 longer journeys. I can often tell when issues are going to return as a slight judder can be felt around 1500 RPM and it wont hold steady, this seems less apparent the more full the fuel tank is.

After my last journey I decided it was time to start looking into a fix, these are the codes currently displayed:

P0101 Mass or Volume Air Flow "A" Circuit Range/Performance (note it is no longer fitted with a standard airbox)
P0112 Intake Air Temperature (IAT) Sensor-1 (G42), Circuit Low Input
P0183 Fuel temperature sender A (G81), Short to B+
P1641 Please check DTC Memory of Air Condition ECU
P161A Manufacturer-specific code
P161B Manufacturer-specific code
P161C Manufacturer-specific code
P161D Manufacturer-specific code

At times there has been variations of the same code as well as some others, the things I have already tried as well as memory will serve me are, It had a new MAF before the car was left to sit I found the receipt in the glovebox, cleaned all ground terminals, throttle body and EGR, performed an engine flush and changed oil as well as oil & fuel filter, replaced ambient air temp sensor, coolant temp sensor and thermostat as rad was not getting warm at all.

I'm sure I've forgotten things and it all looks a huge mess to me but any insight or guidance as what to try next would be hugely appreciated, I'm not one for giving up although I might have done had I not picked up the car so cheap, once again forgive me if this is hard to follow or in the wrong place entirely I am completely new to this.

Thanks in advance.
EBC Brakes Direct - picture of brake discs and pads