Ok, so a bit more info.
Whilst I can access all gears whilst normal driving, it wont rev past 2000rpm to change up until it reaches the top gear.
Also, its completely gutless when going up hill and essentially wont accelerate regardless of how hard you put your foot down.
Looked at the fault codes and found the following:
P1685 - SKIM invalid key
P0100 - Mass/ volume airflow circuit
P0235 Turbo boost sensor circuit A
P0201 - Injector 1 circuit
P0202 - Injector 2 circuit
P0203 - Injector 3 circuit
P0204 - Injector 4 circuit
Now, I have no idea how long those codes have been on their for and if they relate to any past issues.
Again, any help warmly recieved