Interesting one this. First job Friday morning, customer had been driving around since 6:30am

to get car hot enough to demonstrate fault.
Petrol Mondeos don't seem to be as much bother as the TDCIs!
Apparently after being driven for over an hour, car loses power and the hotter it gets the worse it gets. Went out with customer, and sure enough after a few miles, car holds back and if kept on full throttle car goes even slower.
Stopped on side of road, got customer to rev car,wouldn't rev over 4k, sounded like it had anti-lag

and exhaust was 'hissing' as if restricted.....
Went back to garage, no codes in ECU, car had been elsewhere and had new cat and EGR valve, but when these didn't fix it they had ran out of ideas and advised to go to main dealer.
Got car to fault in workshop, again sounded restricted through exhaust, so undone exhaust after cat, still the same, undone exhaust before cat, still the same but LOUD.
Hmmm...
As ever went back to basics. Fuel pressure gauge on the rail (returnless system, FPR part of in-tank pump), started up, over 3.5bar, but went down to 2.5bar when revved up, but not faulting.
Left running a little longer, car started faulting and fuel pressure went down to 1bar when revving. (Should be 3.8bar and maintain it when running) filter is recent and OK.
Awaiting authority to fit new in-tank pump.