I was driving in weekend heavy traffic and suddenly noticed that my exhaust got louder. Noise is obviously coming from the engine side and not the muffler end. Almost as if there is suddenly a hole somewhere. Car is idling fine, power seems there, just much louder and certainly does not sound right. Car was serviced on Thursday. Any suggestions of what I could check before I can get it to the mechanic? Will plugging into VCDS be of any help?