EPC light and Power Loss!!!

Hi guys, on the way home this evening, i accelerated to approx. 85mph (joining a motorway:rolleyes:) then flicked on the cruise control. Pretty much instantly the car lost all engine power and the ESP and EPC lights came on. After pulling to the hard shoulder i noticed the engine noise had not changed but the exhaust note sounded like a Helicopter!

After switching the engine off and on again, all the above issues cleared:confused:.

Gave it another blast on the motorway and nothing happened, just went back to the usual turbo cutting out and re-setting after turning off and on again!

Any advice on wherebouts to start investigating or is a visit to a main dealer the likely answer?

Thanks for any replies