Hello Scotty. I have and Indian car equipped with Fiat sourced 1.3L multijet diesel engine. & The query is, Sometimes even after crossing required revs for turbo, car feels totally dead like it doesn't want to move & very poor throttle response. Further It takes hell lot of time to reach required RPMs. Sometimes this problem totally disappears itself and sometimes suddenly it comes again. Recently serviced at authorised service center they told me to clean EGR valve and some OBD scanning. Even after that it's the exact same situation. And it this happens occasionally like 50-50. Half of the time it runs good. But suddenly it refuses to throttle. And my car has clocked only around 20k miles. You're going amazing with your automobile knowledge. An Indian man needs your suggestions.
P.S. - Does EGR Valve cleaning helps in throttle response? Because EGR Valve in mainly for better emissions values. Infact without EGR valve car will always run with fresh fuel and will give better performance.