Hi everyone. 
I seek wisdom from you. 
As above, my 2009 2.0 petrol , non turbo S max hesitates every single gear change. 
Sometimes nearly stalls especially when cold.  
Needs revs and careful clutch control all the time and rarely had a smooth transition between gears. 
Also feels a bit underpowered. 
Then again I suppose it’s quite a big car. 
Any advice would be greatly appreciated. 
I’m skint so expensive trouble shooting is not an option. 
The only positive thing is that it’s a consistent problem. 
Thanks in advance. 

How long has this been going on a when was it last serviced? Check your air filter straight away, you might have had a field mouse or a squirrel make a home in there and blocked it up! You try running breathing through a straw, you'd struggle and so will your engine. 

If the air filter is clear &/or all other filters have been changed and you are still getting the hesitation, it could be a MAF sensor or one of the other ones that measure crank or camshaft position.

The ECU can extrapolate/guess what amount of air is going into the engine if the MAF is giving bad or impossible reasons. It can do that by smelling the exhaust fuel air mix, but that isn't great and will give a very poor driving experience.

MAF sensors are fairly cheap and very easy to replace if an attempt at cleaning them fails. 

Find a garage that will plug it in for you to check all your main sensor readings. If all your sensors are bob on, then possibly a vacuum hose has a crack or split in it that is causing pulses in the vacuum which can also cause poor engine performance. 

Hope you can get it sorted.

Thank you for that. 
I’ll see what I can find. 

I added a little more detail and corrected some typos! Autocorrect sucks sometimes! 

Thanks for your input. 
I’ve just had a P0400 eml come up. 
egr fault. 
 I didn’t think this engine had an egr system. Has it? 
 It’s non turbo but it really needs one. 
And why would Ford market a car with little power AND one gear less? 
 Bonkers 

This engine does have an EGR at the end of the head above the gearbox.

I'm amazed anyone bought these new.  This is the Mk6 Fiesta ST engine.  It's useless in a heavy Mondeo.  I can't even imagine how bad it must be in an S-Max!