As Steve and Stevey have already mentioned, P2002 is caused by a blocked EGR cooler, though it's worth doing a voltage check on the G450 sensors too because that's the pressure feedback.
I was strongly advised to not delete the EGR cooler, so to avoid failure of components/engine from overheating 12-18 months later.
You could be lucky and get away with replacing an £80 sensor vs. £1k for an EGR valve and cooler replacement, but you're already experiencing it getting hot quickly, so chances are it's blocked.