Ford fiesta mk7🚀1.6 TDCI egr valve clean +fitting 

Chris cleaning the egr helped enormously, but over the last month my son had the drive train warning ⚠️ light up,I took off his diesel fuel filter ,un screwed the plug in the centre and filled the filter with liquid moly purge,I filled the flow and return so we had no air in the system. Connected it back up and started the car low revs and high,it worked a treat no more lymph mode.

Partially, lots of black smoke running better now,also there are sensors just after the turbo on the main turbo pipe which you can clean

Small car 1600cc engine ram it all in no space for anything. Like keyhole surgery. But once you remove a few parts it makes the job easier