Join Date: Dec 2012
Location: Northern Ireland
I have the same car/year etc and had what sounds like the same problem.
For me it was a burst silicone pipe, the air escaping is what caused the rushing air sound and accounted for the lack of power. The warning might not come on unless he's pushing the car, since the sensor won't trip (as in my case). There should however be black smoke when you put your foot down on the accelerator.
A new pipe was just under £100 + fitting, which shouldn't be more than 20 minutes really.
Take it to a garage/dealer. They might have to order in the part, in which case they'll maybe offer to patch the pipe, best not to and just leave it there or drive home slowly.