I set off from a junction today a little quick, and seemed to lose power followed by the traction control light staying on.

Went out later on and the light has gone off but im getting boost surge

I have power upto 3k revs then none untill 4500 then power again

I have a CAI and a Forge Diverter valve, any idea what could be causing it

Could be a faulty N75, opening the wastegate. You need to get the codes read off really, otherwise you'll be fiddling about forever.

Does this only happen when the engine is cold, or is it happening all the time?

I believe the engine will protect itself from high boost while cold. Mine certainly seems to.

Where in Yorkshire are you? So you can find a local member with a code reader/vag com.

The engine was warm when it did it and is now happening everytime

I am just outside of Leeds, will have a look on the Vag com list

Thanks

Might be worth checking all your pipes for leaks.

My TC light came on when my boost hose popped off the intercooler.

Do you have a boost gauge to show you if the boost is ok between 3000 and 4500 revs?

No boost gauge, it doesnt help but its on my to do list

Been out for a look today and Im sure I can hear an air leak just need to try find it

Try the two under the manifold, but be careful as they come wrapped together which can hide the split.

Thanks for your help, got it fixed today

The small pipe on the top of the DV was loose and the DV top was not screwed on very tight seems to have been working since