I purchased a fiesta ST a few months back with a VT330R turbo and stage 3 Revo map. When I got the car it had a few issues which I have listed below:

1) p0016 code: Crankshaft position/camshaft position, bank 1 sensor A - correlation.

2) P083F(00): Clutch pedal position (CPP) switch A/B - correlation. Clutch pedal sticking to the floor when lifting up too quickly.

3) Knocking noise coming from suspension when driving off and going over bumps

4) P0039(73): Turbocharger (TC) bypass valve/supercharger (SC) bypass valve, control - range/performance problem

I drove the car for a while and after a few thousand miles, the expansion tank hose clip failed (apparently a common issue) causing coolant loss and overheating, so I had the Cylinder head, head gasket, puma speed timing belt, ARP head bolts, etc changed. The car was totally fine after but I thought by changing the timing belt it might get rid of the crankshaft/camshaft position code but it was still there.

In terms of the knocking noise, I had the wishbones replaced and the engine mounts. When changing the engine mounts, the battery was disconnected. Once he put it all back together, the car was idling at about 1.1k. I drove it around a bit and a couple days later when I was about to put my foot down, the power cut out, I lost all boost and the engine stalled. When trying to start it again, it just kept cutting out. Eventually, it went into limp mode and started. It's throwing a P006A MAP/MAF Sensor correlation code. I have changed the MAP and MAP sensor to rule them out. I did notice that when the ignition was on, there was a loud ticking noise coming from the boost controller solenoid. I changed that and the noise is no longer there but it is still just going into limp mode. If I clear the code, the car will start for a few seconds, the revs bounce and it stalls and then it goes back into limp mode when I start it again.

Any ideas what it could be? I have tried to add as much information as I can in case anything is linked. For example, it is still showing the P0016 Crankshaft position/camshaft position code but that has been there for months and not caused any issues, not sure if that could be related to the p006a code. Any suggestions at all would be helpful. 2 garages have looked at it and the only suggestions they have left are to reset the ECU but I'll lose the map (I don't have the files)

I take it you bought privately....

if so, you've probably realised you made a mistake buying this particular car. You have my sympathies. 

As a starting point, I'd look at the REVO booklet and look for the dealer stamp of who tuned it and go and take the car to them. At the very least, they'll have the maps stored or available to reload.