Took the car in today to have the parking sensor looked at and the guy plugged the computer in and went through checking for error codes, sure enough he found that one of the sensors wasn't functioning properly but it also said the car was down on boost, he took it out for a drive and said it is nowhere near as quick as it should be (feels pretty fast to me!) so he reckons i need a new diverter valve. Both the parking sensor and the dv valve are covered on my warranty so it isn't so bad, is this a common problem?