Just sent my st focus in for an ecu remap and since I've got it back its been alot quicker at first but now after a couple of days its bit sluggish and been hit and miss with the power. Any ideas on what's wrong or shall I get hold of the garage again?

i would get hold of the garage , somethings going a miss by the sounds of it and its best to get them to sort it rather than search for the problem yourself

How old is your ST and what remap did you have?

If it's an uprated remap like bluefin / dreamscience etc and the boost pressure has been increased, then I'd bet it's your solenoid boost valve is failing with the increased pressure.

Have you noticed it only boosts to 1/4 of the gauge for instance when it feels sluggish?

It's an 07. It was a bluefin remap. Yes the gauge isn't going the full way round when it's performing poorly

It's sticking on 1/4

Boost solenoid valve then I'd guess - I had to get a new one when I Bluefin'd mine too.

Standard Ford one is about £40 from Ford or a specialist:
http://j-w-racing.co.uk/product.php/8096/3089/genuine_ford_boost_solenoid___ford_focus_st

Or you could go for an uprated one for £80 ish:
http://j-w-racing.co.uk/product.php/8236/3089/elevate_heavy_duty_boost_solenoid___ford_focus_st

Thanks very much mate, ill have a look

Even though it is more than likely to be the above, best get in contact with the garage anyway just to preserve any warranty on the work you have as standard.

Thanks for your help folks