Help when I hit 50mph while entering a motorway I get a engine systems fault light on. After plugging in a diagnostics machine it reads no error codes. However a couple of suggestions I've had are maf sensor low which I've checked and cleaned also egr valve which I've cleaned and I still have the problem. Any help gretfully received. 

what did you plug in? not all tools are equal, a lot of ford codes cant be read by a generic reader

Not sure I just borrowed it of a friend who told me to try it. Of course it didn't work haha your right. But doesn't hel me as I'm still at a loss. Like I say I cleaned egr and maf sensor. 

blocked fuel filter restricting fuel flow at a point of high fuel demand?

Grab one of these

https://tunnelrat-electronics.fwscart.com/USB_Auto_Switch_Modified_ELM327/p4541936_19965062.aspx

Then go get Forscan for free

If you have a laptop your sorted, if you dont then android should do the job but will cost you a few quid on top of the device, iphones.... no idea, but you can start by getting an android phone 🙂

I have forscan on my iphone, it was about six quid for the app, I think android is same price. it is actually forscan lite on andriod or iphone, it does not have as much functionality as the free windows version. Lite can do not key programming, I don't know what other differences there might be. But if you have a smart phone on you all the time and keep the fault code reader in your glovebox , it is there to use at any time. More convenient than getting your windows laptop out.  ( i have the wireless one and the usb one, both from that same seller). When my previous fiesta 1.6tdci was playing up going into limp mode, there was a fault code for low fuel pressure. New fuel filter fixed it.