Thanks for your collective help. I've cleaned the sensors today and I'm down to the following error codes:
(9,6) EGR INLET THROTTLE OPEN LOAD, (LOGGED).
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(13,6) EGR INLET THROTTLE SHORT CIRCUIT, (CURRENT).
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(21,4) DRIVER DEMAND 1 OUT OF RANGE (LOGGED).
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(21,5) DRIVER DEMAND 2 OUT OF...