Good morning Ford owners! 
I have had my 2007 fiesta 1.6 diesel for almost 2 years now. 
I have had the same problem with it since I got it. It’s a bit tricky to explain so bare with…

The car has power, is quite a fast little thing really, it’s only standard, nothing special, just a 3 door Zetec Climate with the auto lights and wipers 👌🏻 
 

The problem…

I can floor it all the way to 70, 80, 90 etc absolutely fine, no problems, I can change speeds from 50-90 without issues. The problem is when I’m cruising along.  If I sit at a set speed, whether it’s 50, 60, or 70, sometimes, more often than not, after anywhere between 2-5 minutes, I’ll go to overtake a car, put my foot down, and it’s as if the turbo has sort of fallen asleep? It just won’t accelerate very fast at all, it will still get me to about 85, but it’s very slow getting there, there is no engine lights, it isn’t in ‘limp mode’ as such.
 

BUT

If I flick off the ignition and back on for literally a millisecond, (with it neutral or the clutch pressed) the power comes back, and I’m off again for a little while until I cruise again.
Not so bad in the day time, but in the night time, I have to wait till there’s no other cars around, because my lights go off and back on again, people will think I’m flashing them, or just think I’m a tit lol.
 I’ve put up with this for the last 18 months now and I’m sick of it. 

We drove from Essex down to Cornwall in the summer and I lost count how many times I had to flick it off and on again to regain the power. 
 If I was to leave it without flicking it off and on again, and carry on driving it for about 30 minutes varying the speed, eventually the EML will come on, and the code it throws up is sometimes EGR stuck open, or sometimes it’s EGR stuck closed, reset codes, light goes off, but problem will still happen.

I have changed the EGR after 6 months of ownership, cost about £150, didn’t solve it. 
I changed the throttle body, didn’t solve it. 
I changed the fuel pressure sensor, didn’t solve it. 
I changed the fuel filter only last week, didn’t solve it. 
I have had the EGR parameters reset last week, didn’t solve it. 
 

The other thing is that it is very intermittent, it can last days without doing it, or can do it 5 times in a short period of time on a journey. 
 

When getting the EGR parameters reset, it lasted 4 days, and I honestly thought it had cured it, but it hasn’t and I’m gutted. 

I was told by my mechanics that these engines that they use in the Citroens and Peugeots are notorious for throwing up an EML and an EGR fault code for a dying turbo, but he said it wouldn't be going on for this long, the turbo would have given up completely by now. 
 

I was told by another mechanic that if I change the fuel filter and get the EGR parameters reset, it should solve the problems, it still hasn’t. 
 

WHAT ELSE COULD IT BE?!!! 

I have done 30,000 miles since buying it in June 2020, it gets used a lot, I don’t drive it like a granny, so it’s not clogging up, but I’m lost and don’t know where else to go! 

I’m taking it to Manchester in a few weeks, and I dread how many times I have to flick it off and on again  

Any advice is welcome. Thanks for the read! 

The EGR Valves on these engines are exactly the same as the ones that are fitted to the French versions of this engine except for their internal electronics, which work on different voltage parameters, and if an aftermarket EGR  is listed for both Ford and French engines then it will not work properly on one of them and even if it is just listed for Ford then it may not be the correct one.

The original ones were made by Valeo and have different part numbers for the different engines.

That doesn't mean that I think the EGR is your problem.

If you want to check if the Turbo is behaving itself then get set up with FORScan, preferably the phone version unless you fancy driving around with an open Laptop and a cable draped over you.

Bring up PID's for MAP, MAF, VSS, RPM Accelerator Position and any other for the Turbo and EGR, especially a Turbo Vane one if there is one and take the car for a long drive until the problem occurs, then analyse the Live Data when you get home.

There may or may not be a PID listed for Turbo Boost, but on a Diesel engine the MAP is the same thing. The MAP should go up along with the MAF and the Turbo Vanes should change too when you try to accelerate from a steady speed.

I can’t really offer any help other than to say I had a 2007 fiesta 1.6tdci and I’m pretty sure the turbo was fixed vane not variable vane.  I did about 150k miles in mine and did not have this trouble. My brother then owned it and for most of his time the eml was on showing egr fault code but it still drove 100% ok.